Reference Documentation by Topic/Functionality

Topics covered in this chapter:

This section lists all functions, controls, and attributes of the Optimizer by topics. The topics comprise problem creation, modification, and the solution process itself as well as querying the solution status and values to quickly get started with the Optimizer. Other intermediate and advanced topics include, but are not limited to Infeasibility analysis, solver customization through callback functions, or solving optimization problems with multiple objectives.

Every function, control or attribute in this section is displayed together with its main and perhaps a secondary topic label.

Barrier

Reference section for functions, controls, and attributes related to the Barrier Algorithm, which the Optimizer uses to solve linear programming problems (LPs) as standalone optimization problems or as relaxations during the Branch and Bound Search.

Barrier library functions

XPRSaddcbbariteration	Declares a barrier iteration callback function, called after each iteration during the interior point algorithm, with the ability to access the current barrier solution/slack/duals or reduced cost values, and to ask barrier to stop. [ Barrier, Callback]
XPRSaddcbbarlog	Declares a barrier log callback function, called at each iteration during the interior point algorithm. [ Barrier, Callback]
XPRScrossoverlpsol	Provides a basic optimal solution for a given solution of an LP problem. [ Barrier, LP]
XPRSgetlastbarsol	Used to obtain the last barrier solution values following optimization that used the barrier solver. [ Barrier, Solution]
XPRSremovecbbariteration	Removes a barrier iteration callback function previously added by XPRSaddcbbariteration. [ Barrier, Callback]
XPRSremovecbbarlog	Removes a Newton barrier log callback function previously added by XPRSaddcbbarlog. [ Barrier, Callback]

Barrier controls

ALGAFTERCROSSOVER	The algorithm to be used for the final clean up step after the crossover. [ Barrier, LP]
BARALG	This control determines which barrier algorithm is used to solve the problem. [ Barrier, LP, Primal Dual Hybrid Gradient]
BARCORES	If set to a positive integer it determines the number of physical CPU cores assumed to be present in the system by the barrier and hybrid gradient algorithms. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
BARCRASH	Newton barrier and hybrid gradient: This determines the type of crash used for the crossover. [ Barrier, Primal Dual Hybrid Gradient]
BARDUALSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, representing the tolerance for dual infeasibilities. [ Barrier, Primal Dual Hybrid Gradient, Tolerances]
BARFAILITERLIMIT	Newton barrier: The maximum number of consecutive iterations that fail to improve the solution in the barrier algorithm. [ Barrier, Limits]
BARFREESCALE	Defines how the barrier algorithm scales free variables. [ Barrier]
BARGAPSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, representing the tolerance for the relative duality gap. [ Barrier, Primal Dual Hybrid Gradient]
BARGAPTARGET	Newton barrier: The target tolerance for the relative duality gap. [ Barrier]
BARINDEFLIMIT	Newton Barrier. [ Barrier, Limits]
BARITERATIVE	The maximum number of barrier iterations in which an iterative solver is used instead of the Cholesky decomposition. [ Barrier]
BARITERLIMIT	Newton barrier: The maximum number of iterations. [ Barrier, Limits]
BARKERNEL	Newton barrier: Defines how centrality is weighted in the barrier algorithm. [ Barrier]
BARLARGEBOUND	Threshold for the barrier to handle large bounds. [ Barrier]
BAROBJPERTURB	Defines how the barrier perturbs the objective. [ Barrier]
BAROBJSCALE	Defines how the barrier scales the objective. [ Barrier, Numerics]
BARORDER	Newton barrier: This controls the Cholesky factorization in the Newton-Barrier. [ Barrier]
BARORDERTHREADS	If set to a positive integer it determines the number of concurrent threads for the sparse matrix ordering algorithm in the Newton-barrier method. [ Barrier, Parallel]
BAROUTPUT	Newton barrier and hybrid gradient: This specifies the level of solution output provided. [ Barrier, Logging, Primal Dual Hybrid Gradient]
BARPERTURB	Newton barrier: In numerically challenging cases it is often advantageous to apply perturbations on the KKT system to improve its numerical properties. [ Barrier, Numerics]
BARPRESOLVEOPS	Newton barrier: This bit-vector (see Section .) controls the Newton-Barrier specific presolve operations. [ Barrier, Bit-vector, Presolve]
BARPRIMALSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, indicating the tolerance for primal infeasibilities. [ Barrier, Primal Dual Hybrid Gradient, Tolerances]
BARREFITER	Newton barrier: After terminating the barrier algorithm, further refinement steps can be performed. [ Barrier]
BARREGULARIZE	This bit-vector control (see Section .) determines how the barrier algorithm applies regularization on the KKT system. [ Barrier, Bit-vector]
BARRHSSCALE	Defines how the barrier scales the right hand side. [ Barrier, Numerics]
BARSOLUTION	This determines whether the barrier has to decide which is the best solution found or return the solution computed by the last barrier iteration. [ Barrier]
BARSTART	Controls the computation of the starting point and warm-starting for the Newton barrier and the hybrid gradient algorithms. [ Barrier, Primal Dual Hybrid Gradient]
BARSTARTWEIGHT	Newton barrier: This sets a weight for the warm-start point when warm-start is set for the barrier algorithm. [ Barrier]
BARSTEPSTOP	Newton barrier: A convergence parameter, representing the minimal step size. [ Barrier]
BARTHREADS	If set to a positive integer it determines the number of threads implemented to run the Newton-barrier and hybrid gradient algorithms. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
CHOLESKYALG	Newton barrier: type of Cholesky factorization used; bit-vector-control (see Section .). [ Barrier, Bit-vector]
CHOLESKYTOL	Newton barrier: The tolerance for pivot elements in the Cholesky decomposition of the normal equations coefficient matrix, computed at each iteration of the barrier algorithm. [ Barrier]
CROSSOVER	Newton barrier and hybrid gradient: This control determines whether the barrier method will cross over to the simplex method when at optimal solution has been found, to provide an end basis (see XPRSgetbasis, XPRSwritebasis) and advanced sensitivity analysis information (see XPRSobjsa, XPRSrhssa, XPRSbndsa). [ Barrier, Primal Dual Hybrid Gradient]
CROSSOVERACCURACYTOL	Newton barrier: This control determines how crossover adjusts the default relative pivot tolerance. [ Barrier, Primal Dual Hybrid Gradient]
CROSSOVERITERLIMIT	Newton barrier and hybrid gradient: The maximum number of iterations that will be performed in the crossover procedure before the optimization process terminates. [ Barrier, Primal Dual Hybrid Gradient]
CROSSOVEROPS	Newton barrier and hybrid gradient: a bit-vector (see Section .) for adjusting the behavior of the crossover procedure. [ Barrier, Bit-vector, Primal Dual Hybrid Gradient]
CROSSOVERTHREADS	Determines the maximum number of threads that parallel crossover is allowed to use. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
DENSECOLLIMIT	Newton barrier: Columns with more than DENSECOLLIMIT elements are considered to be dense. [ Barrier, LP]
PREANALYTICCENTER	Determines if analytic centers should be computed and used for variable fixing and the generation of alternative reduced costs (-1: Auto 0: Off, 1: Fixing, 2: Redcost, 3: Both) [ Barrier, Presolve]

Barrier attributes

BARAASIZE	Number of nonzeros in AA^T. [ Barrier]
BARCGAP	Convergence criterion for the Newton barrier algorithm. [ Barrier]
BARCONDA	Absolute condition measure calculated in the last iteration of the barrier algorithm. [ Barrier]
BARCONDD	Condition measure calculated in the last iteration of the barrier algorithm. [ Barrier]
BARCROSSOVER	Indicates whether or not the basis crossover phase has been entered. [ Barrier]
BARDENSECOL	Number of dense columns found in the matrix. [ Barrier]
BARDUALINF	Sum of the dual infeasibilities for the Newton barrier algorithm. [ Barrier]
BARDUALOBJ	Dual objective value calculated by the Newton barrier algorithm. [ Barrier]
BARITER	Number of Newton barrier iterations. [ Barrier]
BARLSIZE	Number of nonzeros in L resulting from the Cholesky factorization. [ Barrier]
BARPRIMALINF	Sum of the primal infeasibilities for the Newton barrier algorithm. [ Barrier]
BARPRIMALOBJ	Primal objective value calculated by the Newton barrier algorithm. [ Barrier]
BARSING	Number of linearly dependent binding constraints at the optimal barrier solution. [ Barrier]
BARSINGR	Regularized number of linearly dependent binding constraints at the optimal barrier solution. [ Barrier]
CROSSOVERITER	Number of simplex iterations performed in crossover. [ Barrier, LP]

Bit-vector

Reference section for all bit-vector controls of the Optimizer. See Section Bit-vector controls for more details on bit-vector controls.

Bit-vector controls

BACKGROUNDSELECT	Bit-vector control (see Section .) to select which tasks to run in background jobs (for example in parallel to the root cut loop). [ Bit-vector, Heuristics, Root]
BARHGOPS	Bit-vector control (see Section .) options for the hybrid gradient algorithm. Bits 1, 2 and 3 control which norms of the coefficient matrix are used for solution normalization. The normalization factor is the maximum of the selected norms. By default, or if all three bits are set to 0, the infinity norm is used. The omega parameter referenced in bits 4, 5 and 6 is a measure of the relative magnitudes of the objective and the right-hand side. [ Bit-vector, Primal Dual Hybrid Gradient]
BARPRESOLVEOPS	Newton barrier: This bit-vector (see Section .) controls the Newton-Barrier specific presolve operations. [ Barrier, Bit-vector, Presolve]
BARREGULARIZE	This bit-vector control (see Section .) determines how the barrier algorithm applies regularization on the KKT system. [ Barrier, Bit-vector]
CHOLESKYALG	Newton barrier: type of Cholesky factorization used; bit-vector-control (see Section .). [ Barrier, Bit-vector]
CLAMPING	This bit-vector control (see Section .) allows for the adjustment of returned solution values such that they are always within bounds. [ Bit-vector, Numerics, Solution]
CRASH	Simplex: This determines the type of crash used when the algorithm begins. [ Bit-vector, LP, Simplex]
CROSSOVEROPS	Newton barrier and hybrid gradient: a bit-vector (see Section .) for adjusting the behavior of the crossover procedure. [ Barrier, Bit-vector, Primal Dual Hybrid Gradient]
CUTSELECT	A bit-vector (see Section .) providing detailed control of the cuts created for the root node of a MIP solve. Use TREECUTSELECT to control cuts during the tree search. [ Bit-vector, Cuts, Root]
DUALIZEOPS	Bit-vector control (see Section .) for adjusting the behavior when a problem is dualized. [ Bit-vector, LP]
DUALSTRATEGY	This bit-vector control (see Section .) specifies the dual simplex strategy. [ Bit-vector, LP, Simplex]
HEURSEARCHBACKGROUNDSELECT	Bit-vector control (see Section .) to select which large neighborhood searches to run in the background (for example in parallel to the root cut loop). [ Bit-vector, Heuristics, Root]
HEURSEARCHROOTSELECT	A bit-vector control (see Section .) for selecting which local search heuristics to apply on the root node of a MIP solve. Use HEURSEARCHTREESELECT to control local search heuristics during the tree search. [ Bit-vector, Heuristics, Root]
HEURSEARCHTREESELECT	A bit-vector control (see Section .) for selecting which local search heuristics to apply during the tree search of a MIP solve. Use HEURSEARCHROOTSELECT to control local search heuristics on the root node. [ Bit-vector, Branch and Bound Search, Heuristics]
IISOPS	Selects which part of the restrictions (bounds, constraints, entities) should always be kept in an IIS. [ Bit-vector, Infeasibility]
LPFLAGS	A bit-vector control (see Section .) which defines the algorithm for solving an LP problem or the initial LP relaxation of a MIP problem. [ Bit-vector, LP, Root]
MIPPRESOLVE	Branch and Bound: Type of integer processing to be performed. [ Bit-vector, Branch and Bound Search, Presolve]
MULTIOBJOPS	Modifies the behaviour of the optimizer when solving multi-objective problems. [ Bit-vector, Multiobjective]
PREPERMUTE	This bit-vector control (see Section .) specifies whether to randomly permute rows, columns and MIP entities when starting the presolve. With the default value 0, no permutation will take place. [ Bit-vector, Presolve, Problem Transformation]
PRESOLVEOPS	This bit-vector control (see Section .) specifies the operations which are performed during the presolve. [ Bit-vector, Presolve]
PRESORT	This bit-vector control (see Section .) specifies whether to sort rows, columns and MIP entities by their names when starting the presolve. With the default value 0, no sorting will take place. [ Bit-vector, Presolve, Problem Transformation]
PRIMALOPS	Primal simplex: allows fine tuning the variable selection in the primal simplex solver. [ Bit-vector, LP, Simplex]
QSIMPLEXOPS	Controls the behavior of the quadratic simplex solvers via a bit-vector (see Section .). [ Bit-vector, Quadratic, Simplex]
REFINEOPS	This specifies when the solution refiner should be executed to reduce solution infeasibilities. [ Bit-vector, Solution Refinement]
SCALING	This bit-vector control (see Section .) determines how the Optimizer will rescale a model internally before optimization. If set to 0, no scaling will take place. [ Bit-vector, Numerics, Problem Transformation]
TREECUTSELECT	A bit-vector (see Section .) providing detailed control of the cuts created during the tree search of a MIP solve. Use CUTSELECT to control cuts on the root node. [ Bit-vector, Branch and Bound Search, Cuts]
TREEDIAGNOSTICS	A bit-vector (see Section .) providing control over how various tree-management-related messages get printed in the tree log file during the branch-and-bound search. [ Bit-vector, Branch and Bound Search, Logging]

Bit-vector attributes

PRESOLVESTATE

Problem status as a bit-vector (compare Section .).
[ Bit-vector, Presolve]

Branch and Bound Search

Reference section for functions, controls, and attributes related to the Branch and Bound Search.

Branch and Bound Search library functions

XPRSaddcbinfnode	Declares a user infeasible node callback function, called after the current node has been found to be infeasible during the Branch and Bound search. [ Branch and Bound Search, Callback]
XPRSaddcbnewnode	Declares a callback function that will be called every time a new node is created during the branch and bound search. [ Branch and Bound Search, Callback]
XPRSaddcbnodecutoff	Declares a user node cutoff callback function, called every time a node is cut off as a result of an improved integer solution being found during the branch and bound search. [ Branch and Bound Search, Callback]
XPRSaddcbnodelpsolved	Declares a callback function, called during the branch and bound search, after the LP relaxation has been solved for the current node, but before any internal cuts and heuristics have been applied. [ Branch and Bound Search, Callback]
XPRSaddcboptnode	Declares an optimal node callback function, called during the branch and bound search, after the LP relaxation has been solved for the current node, and after any internal cuts and heuristics have been applied, but before the Optimizer checks if the current node should be branched. [ Branch and Bound Search, Callback]
XPRSaddcbprenode	Declares a preprocess node callback function, called before the LP relaxation of a node has been optimized, so the solution at the node will not be available. [ Branch and Bound Search, Callback]
XPRSremovecbinfnode	Removes a user infeasible node callback function previously added by XPRSaddcbinfnode. [ Branch and Bound Search, Callback]
XPRSremovecbnewnode	Removes a new-node callback function previously added by XPRSaddcbnewnode. [ Branch and Bound Search, Callback]
XPRSremovecbnodecutoff	Removes a node-cutoff callback function previously added by XPRSaddcbnodecutoff. [ Branch and Bound Search, Callback]
XPRSremovecbnodelpsolved	Removes a node callback function previously added by XPRSaddcbnodelpsolved. [ Branch and Bound Search, Callback]
XPRSremovecboptnode	Removes a node-optimal callback function previously added by XPRSaddcboptnode. [ Branch and Bound Search, Callback]
XPRSremovecbprenode	Removes a preprocess node callback function previously added by XPRSaddcbprenode. [ Branch and Bound Search, Callback]

Branch and Bound Search controls

BACKTRACK	Branch and Bound: Specifies how to select the next node to work on when a full backtrack is performed. [ Branch and Bound Search]
BACKTRACKTIE	Branch and Bound: Specifies how to break ties when selecting the next node to work on when a full backtrack is performed. [ Branch and Bound Search]
BREADTHFIRST	The number of nodes to include in the best-first search before switching to the local first search (NODESELECTION = 4). [ Branch and Bound Search]
CONFLICTCUTS	Branch and Bound: Specifies how cautious or aggressive the optimizer should be when searching for and applying conflict cuts. [ Branch and Bound Search]
CUTDEPTH	Branch and Bound: Sets the maximum depth in the tree search at which cuts will be generated. [ Branch and Bound Search, Cuts]
CUTFACTOR	Limit on the number of cuts and cut coefficients the optimizer is allowed to add to the matrix during tree search. [ Branch and Bound Search, Cuts]
CUTFREQ	Branch and Bound: This specifies the frequency at which cuts are generated in the tree search. [ Branch and Bound Search, Cuts]
CUTSTRATEGY	Branch and Bound: This specifies the cut strategy. [ Branch and Bound Search, Cuts]
DEFAULTALG	This selects the algorithm that will be used to solve LPs, standalone or during MIP optimization. [ Branch and Bound Search, LP]
HEURDEPTH	Branch and Bound: Sets the maximum depth in the tree search at which heuristics will be used to find MIP solutions. [ Branch and Bound Search, Heuristics]
HEURFREQ	Branch and Bound: This specifies the frequency at which heuristics are used in the tree search. [ Branch and Bound Search, Heuristics]
HEURSEARCHFREQ	Branch and Bound: This specifies how often the local search heuristic should be run in the tree. [ Branch and Bound Search, Heuristics]
HEURSEARCHTREESELECT	A bit-vector control (see Section .) for selecting which local search heuristics to apply during the tree search of a MIP solve. Use HEURSEARCHROOTSELECT to control local search heuristics on the root node. [ Bit-vector, Branch and Bound Search, Heuristics]
LOCALCHOICE	Controls when to perform a local backtrack between the two child nodes during a dive in the branch and bound tree. [ Branch and Bound Search]
MAXLOCALBACKTRACK	Branch-and-Bound: How far back up the current dive path the optimizer is allowed to look for a local backtrack candidate node. [ Branch and Bound Search]
MAXNODE	Branch and Bound: The maximum number of nodes that will be explored. [ Branch and Bound Search, Limits]
MIPADDCUTOFF	Branch and Bound: The amount to add to the objective function of the best integer solution found to give the new CURRMIPCUTOFF. [ Branch and Bound Search, Limits]
MIPCOMPONENTS	Determines whether disconnected components in a MIP should be solved as separate MIPs. [ Branch and Bound Search]
MIPCONCURRENTNODES	Sets the node limit for when a winning solve is selected when concurrent MIP solves are enabled. [ Branch and Bound Search, Limits]
MIPCONCURRENTSOLVES	Selects the number of concurrent solves to start for a MIP. [ Branch and Bound Search]
MIPFRACREDUCE	Branch and Bound: Specifies how often the optimizer should run a heuristic to reduce the number of fractional integer variables in the node LP solutions. [ Branch and Bound Search, Root]
MIPKAPPAFREQ	Branch and Bound: Specifies how frequently the basis condition number (also known as kappa) should be calculated during the branch-and-bound search. [ Branch and Bound Search, Numerics]
MIPPRESOLVE	Branch and Bound: Type of integer processing to be performed. [ Bit-vector, Branch and Bound Search, Presolve]
MIPRAMPUP	Controls the strategy used by the parallel MIP solver during the ramp-up phase of a branch-and-bound tree search. [ Branch and Bound Search]
MIPRESTART	Branch and Bound: controls strategy for in-tree restarts. [ Branch and Bound Search]
MIPRESTARTFACTOR	Branch and Bound: Fine tune initial conditions to trigger an in-tree restart. [ Branch and Bound Search]
MIPRESTARTGAPTHRESHOLD	Branch and Bound: Initial gap threshold to delay in-tree restart. [ Branch and Bound Search]
MIPTERMINATIONMETHOD	Branch and Bound: How a MIP solve should be stopped on early termination when there are still active tasks in the system. [ Branch and Bound Search, Limits]
MIPTHREADS	If set to a positive integer it determines the number of threads implemented to run the parallel MIP code. [ Branch and Bound Search, Parallel]
MIQCPALG	This control determines which algorithm is to be used to solve mixed integer quadratic constrained and mixed integer second order cone problems. [ Branch and Bound Search, Quadratic]
MUTEXCALLBACKS	Branch and Bound: This determines whether the callback routines are mutexed from within the optimizer. [ Branch and Bound Search, Callback]
NODEPROBINGEFFORT	Adjusts the overall level of node probing. [ Branch and Bound Search, Presolve]
NODESELECTION	Branch and Bound: This determines which nodes will be considered for solution once the current node has been solved. [ Branch and Bound Search]
REFACTOR	Indicates whether the optimization should restart using the current representation of the factorization in memory. [ Branch and Bound Search, Simplex]
TREECOMPRESSION	When writing nodes to the gloal file, the optimizer can try to use data-compression techniques to reduce the size of the tree file on disk. [ Branch and Bound Search, File IO, Memory]
TREECOVERCUTS	Branch and Bound: The number of rounds of lifted cover inequalities generated at nodes other than the root node in the tree. [ Branch and Bound Search, Cuts]
TREECUTSELECT	A bit-vector (see Section .) providing detailed control of the cuts created during the tree search of a MIP solve. Use CUTSELECT to control cuts on the root node. [ Bit-vector, Branch and Bound Search, Cuts]
TREEDIAGNOSTICS	A bit-vector (see Section .) providing control over how various tree-management-related messages get printed in the tree log file during the branch-and-bound search. [ Bit-vector, Branch and Bound Search, Logging]
TREEFILELOGINTERVAL	This control sets the interval between progress messages output while writing tree data to the tree file, in seconds. [ Branch and Bound Search, Logging]
TREEGOMCUTS	Branch and Bound: The number of rounds of Gomory cuts generated at nodes other than the first node in the tree. [ Branch and Bound Search, Cuts]
TREEMEMORYSAVINGTARGET	When the memory used by the branch-and-bound search tree exceeds the limit specified by the TREEMEMORYLIMIT control, the optimizer will try to save memory by writing lower-rated sections of the tree to the tree file. [ Branch and Bound Search, Memory]
TREEQCCUTS	Branch and Bound: Limit on the number of rounds of outer approximation cuts generated for nodes other than the root node, when solving a mixed integer quadratic constrained or mixed integer second order conic problem with outer approximation. [ Branch and Bound Search, Quadratic]

Branch and Bound Search attributes

ACTIVENODES	Number of outstanding nodes. [ Branch and Bound Search]
ATTENTIONLEVEL	A measure between 0 and 1 for how numerically unstable the problem is. [ Branch and Bound Search, Numerics]
BESTBOUND	Value of the best bound determined so far by the MIP search. [ Branch and Bound Search]
CALLBACKCOUNT_OPTNODE	This attribute counts the number of times the optimal node callback set by XPRSaddcboptnode has been called for the current node, including the current callback call. [ Branch and Bound Search, Callback]
CURRENTNODE	The unique identifier of the current node in the tree search. [ Branch and Bound Search]
CURRMIPCUTOFF	The current MIP cut off. [ Branch and Bound Search]
MAXKAPPA	Largest basis condition number (also known as kappa) calculated through all nodes sampled by MIPKAPPAFREQ. [ Branch and Bound Search, Numerics]
MIPBESTOBJVAL	Objective function value of the best integer solution found. [ Branch and Bound Search]
MIPINFEAS	Number of integer infeasibilities, including violations of special ordered sets, at the current node. [ Branch and Bound Search, MIP Entities]
MIPOBJVAL	Objective function value of the last integer solution found. [ Branch and Bound Search, Solution]
MIPSOLNODE	Node at which the last integer feasible solution was found. [ Branch and Bound Search, Solution]
MIPSOLS	Number of integer solutions that have been found. [ Branch and Bound Search, Solution]
MIPSOLTIME	Time at which the last integer feasible solution was found. [ Branch and Bound Search, Solution]
MIPSTATUS	(MIP) solution status. [ Branch and Bound Search]
MIPTHREADID	The ID for the MIP thread. [ Branch and Bound Search]
NODEDEPTH	Depth of the current node. [ Branch and Bound Search]
NODES	Number of nodes solved so far in the MIP search. [ Branch and Bound Search]
OBSERVEDPRIMALINTEGRAL	Value of the (observed) primal integral. [ Branch and Bound Search]
PARENTNODE	The parent node of the current node in the tree search. [ Branch and Bound Search]
PEAKTOTALTREEMEMORYUSAGE	The peak size, in megabytes, that the branch-and-bound search tree reached during the solve. [ Branch and Bound Search, Memory]
RESTARTS	Total number of restarts performed. [ Branch and Bound Search]
TREECOMPLETION	Estimation of the relative completion of the search tree as fraction between 0 and 1. [ Branch and Bound Search]
TREEFILESIZE	The allocated size of the tree file, in megabytes. [ Branch and Bound Search, Memory]
TREEFILEUSAGE	The number of megabytes of data from the branch-and-bound tree that have been saved to the tree file. [ Branch and Bound Search, Memory]
TREEMEMORYUSAGE	The amount of physical memory, in megabytes, currently being used to store the branch-and-bound search tree. [ Branch and Bound Search, Memory]
TREERESTARTS	Number of in-tree restarts performed. [ Branch and Bound Search]

Branching Object

Reference section for functions, controls, and attributes related to branching objects. Branching objects can be used to implement custom user branching strategies.

Branching Object library functions

XPRS_bo_addbounds	Adds new bounds to a branch of a user branching object. [ Branching Object]
XPRS_bo_addbranches	Adds new, empty branches to a user defined branching object. [ Branching Object]
XPRS_bo_addcuts	Adds stored user cuts as new constraints to a branch of a user branching object. [ Branching Object]
XPRS_bo_addrows	Adds new constraints to a branch of a user branching object. [ Branching Object]
XPRS_bo_create	Creates a new user defined branching object for the Optimizer to branch on. [ Branching Object]
XPRS_bo_destroy	Frees all memory for a user branching object, when the object was not stored with the Optimizer. [ Branching Object]
XPRS_bo_getbounds	Returns the bounds for a branch of a user branching object. [ Branching Object]
XPRS_bo_getbranches	Returns the number of branches of a branching object. [ Branching Object]
XPRS_bo_getid	Returns the unique identifier assigned to a branching object. [ Branching Object]
XPRS_bo_getlasterror	Returns the last error encountered during a call to the given branch object. [ Branching Object]
XPRS_bo_getrows	Returns the constraints for a branch of a user branching object. [ Branching Object]
XPRS_bo_setpreferredbranch	Specifies which of the child nodes corresponding to the branches of the object should be explored first. [ Branching Object]
XPRS_bo_setpriority	Sets the priority value of a user branching object. [ Branching Object]
XPRS_bo_store	Adds a new user branching object to the Optimizer's list of candidates for branching. [ Branching Object]
XPRS_bo_validate	Verifies that a given branching object is valid for branching on the current branch-and-bound node of a MIP solve. [ Branching Object]

Branching

Reference section for functions, controls, and attributes related to Branching. All of them affect how problems are subdivided to resolve infeasibilities during the Branch and Bound search.

Branching library functions

XPRSaddcbchgbranchobject	Declares a callback function that will be called after the selection of a MIP entity to branch on. [ Branching, Callback]
XPRSgetdirs	Used to return the directives that have been loaded into a matrix. [ Branching, Problem Information]
XPRSloadbranchdirs	Loads directives into the current problem to specify which MIP entities the Optimizer should continue to branch on when a node solution is integer feasible. [ Branching, Data Input]
XPRSloadpresolvedirs	Loads directives into the presolved matrix. [ Branching, Data Input]
XPRSreaddirs	Reads a directives file to help direct the tree search. [ Branching, File IO]
XPRSremovecbchgbranchobject	Removes a callback function previously added by XPRSaddcbchgbranchobject. [ Branching, Callback]
XPRSstrongbranch	Performs strong branching iterations on all specified bound changes. [ Branching]
XPRSstrongbranchcb	Performs strong branching iterations on all specified bound changes. [ Branching]
XPRSwritedirs	Writes the tree search directives from the current problem to a directives file. [ Branching, File IO]

Branching controls

BRANCHCHOICE	Once a MIP entity has been selected for branching, this control determines which of the branches is solved first. [ Branching]
BRANCHDISJ	Branch and Bound: Determines whether the optimizer should attempt to branch on general split disjunctions during the branch and bound search. [ Branching]
BRANCHSTRUCTURAL	Branch and Bound: Determines whether the optimizer should search for special structure in the problem to branch on during the branch and bound search. [ Branching]
GLOBALSPATIALBRANCHCUTTINGEFFORT	Limits the effort that is spent on creating cuts during spatial branching. [ Branching, Global]
GLOBALSPATIALBRANCHIFPREFERORIG	Whether spatial branchings on original variables should be preferred over branching on auxiliary variables that were introduced by the reformulation of the global solver. [ Branching, Global]
HISTORYCOSTS	Branch and Bound: How to update the pseudo cost for a MIP entity when a strong branch or a regular branch is applied. [ Branching]
PSEUDOCOST	Branch and Bound: The default pseudo cost used in estimation of the degradation associated with an unexplored node in the tree search. [ Branching]
SBBEST	Number of infeasible MIP entities to initialize pseudo costs for on each node. [ Branching]
SBEFFORT	Adjusts the overall amount of effort when using strong branching to select an infeasible MIP entity to branch on. [ Branching]
SBESTIMATE	Branch and Bound: How to calculate pseudo costs from the local node when selecting an infeasible MIP entity to branch on. [ Branching]
SBITERLIMIT	Number of dual iterations to perform the strong branching for each entity. [ Branching, Limits]
SBSELECT	The size of the candidate list of MIP entities for strong branching. [ Branching]
VARSELECTION	Branch and Bound: This determines the formula used to calculate the estimate of each integer variable, and thus which integer variable is selected to be branched on at a given node. [ Branching]

Branching attributes

BRANCHVALUE	The value of the branching variable at a node of the Branch and Bound tree. [ Branching]
BRANCHVAR	The branching variable at a node of the Branch and Bound tree. [ Branching]

Callback

Reference section for functions, controls, and attributes related to the use of callback functions within the Optimizer. Callbacks enable the user to interact with the Optimizer at all stages of the solution process. For example, use callbacks to interrupt the search when a special condition is satisfied, to query or reject certain solutions while the solution process is still running, or to make custom problem modifications.

Callback library functions

XPRS_ge_addcbmsghandler	Declares an output callback function in the global environment, called every time a line of message text is output by any data in the library. [ Callback, Global Environment]
XPRS_ge_removecbmsghandler	Removes a message callback function previously added by XPRS_ge_addcbmsghandler. [ Callback, Global Environment]
XPRSaddcbafterobjective	Declares a callback which will be called after each objective in a multi-objective problem is solved. [ Callback, Multiobjective]
XPRSaddcbbariteration	Declares a barrier iteration callback function, called after each iteration during the interior point algorithm, with the ability to access the current barrier solution/slack/duals or reduced cost values, and to ask barrier to stop. [ Barrier, Callback]
XPRSaddcbbarlog	Declares a barrier log callback function, called at each iteration during the interior point algorithm. [ Barrier, Callback]
XPRSaddcbbeforeobjective	Declares a callback which will be called before each objective in a multi-objective problem is solved. [ Callback, Multiobjective]
XPRSaddcbchecktime	Declares a callback function which is called every time the Optimizer checks if the time limit has been reached. [ Callback, Limits]
XPRSaddcbchgbranchobject	Declares a callback function that will be called after the selection of a MIP entity to branch on. [ Branching, Callback]
XPRSaddcbcomputerestart	Declares a callback to be called when a solve executed in compute mode needs to be restarted. [ Callback, Compute Interface]
XPRSaddcbcutlog	Declares a cut log callback function, called each time the cut log is printed. [ Callback, Logging]
XPRSaddcbcutround	Declares a callback function that is called when the Optimizer could separate cutting planes during the branch and bound search. [ Callback, Cuts]
XPRSaddcbdestroymt	Declares a destroy MIP thread callback function, called every time a MIP thread is destroyed by the parallel MIP code. [ Callback, Parallel]
XPRSaddcbgapnotify	Declares a gap notification callback, to be called when a MIP solve reaches a predefined target, set using the MIPRELGAPNOTIFY, MIPABSGAPNOTIFY, MIPABSGAPNOTIFYOBJ and/or MIPABSGAPNOTIFYBOUND controls. [ Callback, Limits]
XPRSaddcbinfnode	Declares a user infeasible node callback function, called after the current node has been found to be infeasible during the Branch and Bound search. [ Branch and Bound Search, Callback]
XPRSaddcbintsol	Declares a user integer solution callback function, called every time an integer solution is found by heuristics or during the Branch and Bound search. [ Callback, Solution]
XPRSaddcblplog	Declares a simplex log callback function which is called after every LPLOG iterations of the simplex algorithm. [ Callback, LP]
XPRSaddcbmessage	Declares an output callback function, called every time a text line relating to the given XPRSprob is output by the Optimizer. [ Callback, Logging]
XPRSaddcbmiplog	Declares a MIP log callback function, called each time the MIP log is printed. [ Callback, Logging]
XPRSaddcbmipthread	Declares a MIP thread callback function, called every time a MIP worker problem is created by the parallel MIP code. [ Callback, Parallel]
XPRSaddcbnewnode	Declares a callback function that will be called every time a new node is created during the branch and bound search. [ Branch and Bound Search, Callback]
XPRSaddcbnodecutoff	Declares a user node cutoff callback function, called every time a node is cut off as a result of an improved integer solution being found during the branch and bound search. [ Branch and Bound Search, Callback]
XPRSaddcbnodelpsolved	Declares a callback function, called during the branch and bound search, after the LP relaxation has been solved for the current node, but before any internal cuts and heuristics have been applied. [ Branch and Bound Search, Callback]
XPRSaddcboptnode	Declares an optimal node callback function, called during the branch and bound search, after the LP relaxation has been solved for the current node, and after any internal cuts and heuristics have been applied, but before the Optimizer checks if the current node should be branched. [ Branch and Bound Search, Callback]
XPRSaddcbpreintsol	Declares a user integer solution callback function, called when an integer solution is found by heuristics or during the branch and bound search, but before it is accepted by the Optimizer. [ Callback, Solution]
XPRSaddcbprenode	Declares a preprocess node callback function, called before the LP relaxation of a node has been optimized, so the solution at the node will not be available. [ Branch and Bound Search, Callback]
XPRSaddcbpresolve	Declares a callback to be called after presolve has been performed. [ Callback, Presolve]
XPRSaddcbusersolnotify	Declares a callback function to be called each time a solution added by XPRSaddmipsol has been processed. [ Callback, Solution]
XPRSaddmanagedcuts, XPRSaddmanagedcuts64	Adds cuts to the Optimizer's internal cut pool from within the cutround callback set by XPRSaddcbcutround. [ Callback, Cuts]
XPRScopycallbacks	Copies callback functions defined for one problem to another. [ Callback]
XPRSgetcallbackduals	Returns the dual values dual value for this constraint from the solution associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolveduals	Returns the dual values from the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolveredcosts	Returns the reduced costs from the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolveslacks	Returns the slack values from the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolvesolution	Returns the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackredcosts	Returns the reduced costs reduced cost for this variable from the solution associated with the current callback. [ Callback, Solution]
XPRSgetcallbackslacks	Returns the slack values slack value for this constraint from the solution associated with the current callback. [ Callback, Solution]
XPRSgetcallbacksolution	Returns the primal values primal value for this variable from the solution associated with the current callback. [ Callback, Solution]
XPRSremovecbafterobjective	Removes a callback function previously added by XPRSaddcbafterobjective. [ Callback, Multiobjective]
XPRSremovecbbariteration	Removes a barrier iteration callback function previously added by XPRSaddcbbariteration. [ Barrier, Callback]
XPRSremovecbbarlog	Removes a Newton barrier log callback function previously added by XPRSaddcbbarlog. [ Barrier, Callback]
XPRSremovecbbeforeobjective	Removes a callback function previously added by XPRSaddcbbeforeobjective. [ Callback, Multiobjective]
XPRSremovecbchecktime	Removes a callback function previously added by XPRSaddcbchecktime. [ Callback, Limits]
XPRSremovecbchgbranchobject	Removes a callback function previously added by XPRSaddcbchgbranchobject. [ Branching, Callback]
XPRSremovecbcomputerestart	Removes a computerestart callback function previously added by XPRSaddcbcomputerestart. [ Callback, Compute Interface]
XPRSremovecbcutlog	Removes a cut log callback function previously added by XPRSaddcbcutlog. [ Callback, Logging]
XPRSremovecbcutround	Removes a cut round callback function previously added by XPRSaddcbcutround. [ Callback, Cuts]
XPRSremovecbdestroymt	Removes a slave thread destruction callback function previously added by XPRSaddcbdestroymt. [ Callback, Parallel]
XPRSremovecbgapnotify	Removes a callback function previously added by XPRSaddcbgapnotify. [ Callback, Limits]
XPRSremovecbinfnode	Removes a user infeasible node callback function previously added by XPRSaddcbinfnode. [ Branch and Bound Search, Callback]
XPRSremovecbintsol	Removes an integer solution callback function previously added by XPRSaddcbintsol. [ Callback, Solution]
XPRSremovecblplog	Removes a simplex log callback function previously added by XPRSaddcblplog. [ Callback, Logging]
XPRSremovecbmessage	Removes a message callback function previously added by XPRSaddcbmessage. [ Callback, Logging]
XPRSremovecbmiplog	Removes a MIP log callback function previously added by XPRSaddcbmiplog. [ Callback, Logging]
XPRSremovecbmipthread	Removes a callback function previously added by XPRSaddcbmipthread. [ Callback, Parallel]
XPRSremovecbnewnode	Removes a new-node callback function previously added by XPRSaddcbnewnode. [ Branch and Bound Search, Callback]
XPRSremovecbnodecutoff	Removes a node-cutoff callback function previously added by XPRSaddcbnodecutoff. [ Branch and Bound Search, Callback]
XPRSremovecbnodelpsolved	Removes a node callback function previously added by XPRSaddcbnodelpsolved. [ Branch and Bound Search, Callback]
XPRSremovecboptnode	Removes a node-optimal callback function previously added by XPRSaddcboptnode. [ Branch and Bound Search, Callback]
XPRSremovecbpreintsol	Removes a pre-integer solution callback function previously added by XPRSaddcbpreintsol. [ Callback, Solution]
XPRSremovecbprenode	Removes a preprocess node callback function previously added by XPRSaddcbprenode. [ Branch and Bound Search, Callback]
XPRSremovecbpresolve	Removes a presolve callback function previously added by XPRSaddcbpresolve. [ Callback, Presolve]
XPRSremovecbusersolnotify	Removes a user solution notification callback previously added by XPRSaddcbusersolnotify. [ Callback, Solution]

Callback controls

CALLBACKCHECKTIMEDELAY	Minimum delay in milliseconds between two consecutive executions of the CHECKTIME callback in the same solution process [ Callback]
CALLBACKCHECKTIMEWORKDELAY	Minimum delay in work units between two consecutive executions of the CHECKTIME callback in the same solution process [ Callback, Determinism]
CALLBACKFROMMASTERTHREAD	Branch and Bound: specifies whether the MIP callbacks should only be called on the master thread. [ Callback]
MIPABSGAPNOTIFY	Branch and bound: if the gapnotify callback has been set using XPRSaddcbgapnotify, then this callback will be triggered during the tree search when the absolute gap reaches or passes the value you set of the MIPRELGAPNOTIFY control. [ Callback]
MIPABSGAPNOTIFYBOUND	Branch and bound: if the gapnotify callback has been set using XPRSaddcbgapnotify, then this callback will be triggered during the tree search when the best bound reaches or passes the value you set of the MIPRELGAPNOTIFYBOUND control. [ Callback]
MIPABSGAPNOTIFYOBJ	Branch and bound: if the gapnotify callback has been set using XPRSaddcbgapnotify, then this callback will be triggered during the tree search when the best solution value reaches or passes the value you set of the MIPRELGAPNOTIFYOBJ control. [ Callback]
MIPRELGAPNOTIFY	Branch and bound: if the gapnotify callback has been set using XPRSaddcbgapnotify, then this callback will be triggered during the branch and bound tree search when the relative gap reaches or passes the value you set of the MIPRELGAPNOTIFY control. [ Callback]
MUTEXCALLBACKS	Branch and Bound: This determines whether the callback routines are mutexed from within the optimizer. [ Branch and Bound Search, Callback]
SERIALIZEPREINTSOL	Setting SERIALIZEPREINTSOL to 1 will ensure that the preintsol callback is always fired in a deterministic order during a parallel MIP solve. [ Callback, Determinism]

Callback attributes

CALLBACKCOUNT_CUTMGR	This attribute counts the number of times the cut manager callback set by XPRSaddcbcutmgr has been called for the current node, including the current callback call. [ Callback, Cuts]
CALLBACKCOUNT_OPTNODE	This attribute counts the number of times the optimal node callback set by XPRSaddcboptnode has been called for the current node, including the current callback call. [ Branch and Bound Search, Callback]

Compute Interface

Reference section for functions, controls, and attributes related to the Compute Interface.

Compute Interface library functions

XPRS_ge_getcomputeallowed	Query whether the current application is allowed to use the Insight Compute interface. [ Compute Interface, Global Environment]
XPRS_ge_setcomputeallowed	Set whether the current application is allowed to use the Insight Compute interface. [ Compute Interface, Global Environment]
XPRSaddcbcomputerestart	Declares a callback to be called when a solve executed in compute mode needs to be restarted. [ Callback, Compute Interface]
XPRSremovecbcomputerestart	Removes a computerestart callback function previously added by XPRSaddcbcomputerestart. [ Callback, Compute Interface]

Compute Interface controls

COMPUTE	Controls whether the next solve is performed directly or on an Insight Compute Interface. [ Compute Interface]
COMPUTEEXECSERVICE	Selects the Insight execution service that will be used for solving remote optimizations. [ Compute Interface]
COMPUTEJOBPRIORITY	Selects the priority that will be used for remote optimization jobs. [ Compute Interface]
COMPUTELOG	Controls how the run log is fetched when a solve is performed on an Insight Compute Interface. [ Compute Interface]

Compute Interface attributes

COMPUTEEXECUTIONS

The number of solves executed on a compute server.
[ Compute Interface]

Controls and Attributes

Reference section for functions related to setting and querying Controls and Attributes of the Optimizer. The Optimizer provides various problem and solution statistics in the form of user attributes. User controls govern the execution of the solution algorithms within the Optimizer.

Controls and Attributes library functions

XPRScopycontrols	Copies controls defined for one problem to another. [ Controls and Attributes]
XPRSdumpcontrols	Displays the list of controls and their current value for those controls that have been set to a non default value. [ Controls and Attributes]
XPRSgetattribinfo	Accesses the id number and the type information of an attribute given its name. [ Controls and Attributes]
XPRSgetcontrolinfo	Accesses the id number and the type information of a control given its name. [ Controls and Attributes]
XPRSgetdblattrib	Enables users to retrieve the values of various double problem attributes. [ Controls and Attributes]
XPRSgetdblcontrol	Retrieves the value of a given double control parameter. [ Controls and Attributes]
XPRSgetintattrib, XPRSgetintattrib64	Enables users to recover the values of various integer problem attributes. [ Controls and Attributes]
XPRSgetintcontrol, XPRSgetintcontrol64	Enables users to recover the values of various integer control parameters [ Controls and Attributes]
XPRSgetobjdblattrib	Retrieves the value of a given double attribute associated with a multi-objective solve. [ Controls and Attributes, Multiobjective]
XPRSgetobjdblcontrol	Retrieves the value of a given double control parameter associated with an objective function. [ Controls and Attributes, Multiobjective]
XPRSgetobjecttypename	Function to access the type name of an object referenced using the generic Optimizer object pointer XPRSobject. [ Controls and Attributes, Multiobjective]
XPRSgetobjintattrib, XPRSgetobjintattrib64	Retrieves the value of a given integer attribute associated with a multi-objective solve. [ Controls and Attributes, Multiobjective]
XPRSgetobjintcontrol	Retrieves the value of a given integer control parameter associated with an objective. [ Controls and Attributes, Multiobjective]
XPRSgetstrattrib, XPRSgetstringattrib	Enables users to recover the values of various string problem attributes. [ Controls and Attributes]
XPRSgetstrcontrol, XPRSgetstringcontrol	Returns the value of a given string control parameters. [ Controls and Attributes]
XPRSsetdblcontrol	Sets the value of a given double control parameter. [ Controls and Attributes]
XPRSsetdefaultcontrol	Sets a single control to its default value. [ Controls and Attributes]
XPRSsetdefaults	Sets all controls to their default values. [ Controls and Attributes]
XPRSsetintcontrol, XPRSsetintcontrol64	Sets the value of a given integer control parameter. [ Controls and Attributes]
XPRSsetobjdblcontrol	Sets the value of a given double control parameter associated with an objective. [ Controls and Attributes, Multiobjective]
XPRSsetobjintcontrol	Sets the value of a given integer control parameter associated with an objective. [ Controls and Attributes, Multiobjective]
XPRSsetstrcontrol	Used to set the value of a given string control parameter. [ Controls and Attributes]

Controls and Attributes controls

HEURSEARCHCOPYCONTROLS

Select how user-set controls should affect local search heuristics.
[ Controls and Attributes, Heuristics]

Cuts

Reference section for functions, controls, and attributes related to cutting plane separation. Separation denotes the process of deriving new valid inequalities to strengthen the linear (LP) relaxation during the Branch and Bound Search.

Cuts library functions

XPRSaddcbcutround	Declares a callback function that is called when the Optimizer could separate cutting planes during the branch and bound search. [ Callback, Cuts]
XPRSaddcuts, XPRSaddcuts64	Adds cuts directly to the matrix at the current node. [ Cuts]
XPRSaddmanagedcuts, XPRSaddmanagedcuts64	Adds cuts to the Optimizer's internal cut pool from within the cutround callback set by XPRSaddcbcutround. [ Callback, Cuts]
XPRSdelcpcuts	During the branch and bound search, cuts are stored in the cut pool to be applied at descendant nodes. [ Cuts]
XPRSdelcuts	Deletes cuts from the matrix at the current node. [ Cuts]
XPRSgetcpcutlist	Returns a list of cut indices from the cut pool. [ Cuts]
XPRSgetcpcuts, XPRSgetcpcuts64	Returns cuts from the cut pool. [ Cuts]
XPRSgetcutlist	Retrieves a list of cut pointers for the cuts active at the current node. [ Cuts]
XPRSgetcutmap	Used to return in which rows a list of cuts are currently loaded into the Optimizer. [ Cuts]
XPRSgetcutslack	Used to calculate the slack value of a cut with respect to the current LP relaxation solution. [ Cuts]
XPRSloadcuts	Loads cuts from the cut pool into the matrix. [ Cuts, Data Input]
XPRSloaddelayedrows	Specifies that a set of rows in the matrix will be treated as delayed rows during a tree search. [ Cuts, Problem Input]
XPRSloadmodelcuts	Specifies that a set of rows in the matrix will be treated as model cuts. [ Cuts, Data Input]
XPRSremovecbcutround	Removes a cut round callback function previously added by XPRSaddcbcutround. [ Callback, Cuts]
XPRSstorecuts, XPRSstorecuts64	Stores cuts into the cut pool, but does not apply them to the current node. [ Cuts]

Cuts controls

AUTOCUTTING	Should the Optimizer automatically decide whether to generate cutting planes at local nodes in the tree or not? If the CUTFREQ control is set, no automatic selection will be made and local cutting will be enabled. [ Cuts]
COVERCUTS	Branch and Bound: The number of rounds of lifted cover inequalities at the root node. [ Cuts, Root]
CUTDEPTH	Branch and Bound: Sets the maximum depth in the tree search at which cuts will be generated. [ Branch and Bound Search, Cuts]
CUTFACTOR	Limit on the number of cuts and cut coefficients the optimizer is allowed to add to the matrix during tree search. [ Branch and Bound Search, Cuts]
CUTFREQ	Branch and Bound: This specifies the frequency at which cuts are generated in the tree search. [ Branch and Bound Search, Cuts]
CUTSELECT	A bit-vector (see Section .) providing detailed control of the cuts created for the root node of a MIP solve. Use TREECUTSELECT to control cuts during the tree search. [ Bit-vector, Cuts, Root]
CUTSTRATEGY	Branch and Bound: This specifies the cut strategy. [ Branch and Bound Search, Cuts]
GLOBALNLPCUTS	Limit on the number of rounds of outer approximation and convexification cuts generated for the root node, when solving an (MI)NLP to global optimality. [ Cuts, Global]
GLOBALNUMINITNLPCUTS	Specifies the maximum number of tangent cuts when setting up the initial relaxation during a global solve. [ Cuts, Global]
GLOBALTREENLPCUTS	Limit on the number of rounds of outer approximation and convexification cuts generated for each node in the tree, when solving an (MI)NLP to global optimality. [ Cuts, Global]
GOMCUTS	Branch and Bound: The number of rounds of Gomory or lift-and-project cuts at the root node. [ Cuts, Root]
LNPBEST	Number of infeasible MIP entities to create lift-and-project cuts for during each round of Gomory cuts at the root node (see GOMCUTS). [ Cuts, Root]
LNPITERLIMIT	Number of iterations to perform in improving each lift-and-project cut. [ Cuts, Limits]
MAXCUTTIME	The maximum amount of time allowed for generation of cutting planes and reoptimization. [ Cuts, Limits]
MCFCUTSTRATEGY	Level of Multi-Commodity Flow (MCF) cutting planes separation: This specifies how much aggresively MCF cuts should be separated. [ Cuts]
QCCUTS	Branch and Bound: Limit on the number of rounds of outer approximation cuts generated for the root node, when solving a mixed integer quadratic constrained or mixed integer second order conic problem with outer approximation. [ Cuts, Quadratic]
RLTCUTS	Determines whether RLT cuts should be separated in the Xpress Global Solver. [ Cuts, Quadratic]
TREECOVERCUTS	Branch and Bound: The number of rounds of lifted cover inequalities generated at nodes other than the root node in the tree. [ Branch and Bound Search, Cuts]
TREECUTSELECT	A bit-vector (see Section .) providing detailed control of the cuts created during the tree search of a MIP solve. Use CUTSELECT to control cuts on the root node. [ Bit-vector, Branch and Bound Search, Cuts]
TREEGOMCUTS	Branch and Bound: The number of rounds of Gomory cuts generated at nodes other than the first node in the tree. [ Branch and Bound Search, Cuts]

Cuts attributes

CALLBACKCOUNT_CUTMGR	This attribute counts the number of times the cut manager callback set by XPRSaddcbcutmgr has been called for the current node, including the current callback call. [ Callback, Cuts]
CUTROUNDS	Number of rounds of cuts applied to the current node of a branch-and-bound search. [ Cuts]
CUTS	Number of cuts being added to the matrix. [ Cuts]

Data Input

Reference section for functions, controls, and attributes related to the input of auxiliary data into the Optimizer. While not strictly necessary, auxiliary data can be used to customize the solution process.

Data Input library functions

XPRSloadbasis	Loads a basis from the user's areas. [ Data Input, LP]
XPRSloadbranchdirs	Loads directives into the current problem to specify which MIP entities the Optimizer should continue to branch on when a node solution is integer feasible. [ Branching, Data Input]
XPRSloadcuts	Loads cuts from the cut pool into the matrix. [ Cuts, Data Input]
XPRSloaddirs	Loads directives into the matrix. [ Data Input]
XPRSloadlpsol	Loads an LP solution for the problem into the Optimizer. [ Data Input, LP, Solution]
XPRSloadmipsol	Loads a starting MIP solution for the problem into the Optimizer. [ Data Input, MIP Entities, Solution]
XPRSloadmodelcuts	Specifies that a set of rows in the matrix will be treated as model cuts. [ Cuts, Data Input]
XPRSloadpresolvebasis	Loads a presolved basis from the user's areas. [ Data Input, LP]
XPRSloadpresolvedirs	Loads directives into the presolved matrix. [ Branching, Data Input]
XPRSloadsecurevecs	Allows the user to mark rows and columns in order to prevent the presolve removing these rows and columns from the matrix. [ Data Input, Presolve]

Determinism

Reference section for functions, controls, and attributes affecting determinism. In its default settings, the Optimizer behaves deterministically - every invocation of the solution routines for the same input data results not only in the same final solution, but also in a reproducible solution path. This is true even in parallel and independent of the system specs (CPU architecture, number of threads, Operating System) where the process is launched. The controls in this group can be used to drop this reproducibility and should hence be used with utmost care.

Determinism controls

CALLBACKCHECKTIMEWORKDELAY	Minimum delay in work units between two consecutive executions of the CHECKTIME callback in the same solution process [ Callback, Determinism]
DETERMINISTIC	Selects whether to use a deterministic or opportunistic mode when solving a problem using multiple threads. [ Determinism]
MAXMIPTASKS	Branch-and-Bound: The maximum number of tasks to run in parallel during a MIP solve. [ Determinism, Limits, Parallel]
RANDOMSEED	Sets the initial seed to use for the pseudo-random number generator in the Optimizer. [ Determinism]
RESOURCESTRATEGY	Controls whether the optimizer is allowed to make nondeterministic decisions if memory is running low in an effort to preserve memory and finish the solve. [ Determinism, Memory]
SERIALIZEPREINTSOL	Setting SERIALIZEPREINTSOL to 1 will ensure that the preintsol callback is always fired in a deterministic order during a parallel MIP solve. [ Callback, Determinism]
WORKLIMIT	The maximum work (measured in work units) that the Optimizer will run before it terminates. [ Determinism, Limits]

Determinism attributes

WORK	Amount of deterministic algorithmic "work" spent since the invocation of the search process. [ Determinism, Solution Process]

File IO

Reference section for functions, controls, and attributes related to File IO. Use these functions to write and read data from disk into the Optimizer.

File IO library functions

XPRSiiswrite	Writes an LP/MPS/CSV file containing a given Irreducible Infeasible Set (IIS). [ File IO, Infeasibility]
XPRSreadbasis	Instructs the Optimizer to read in a previously saved basis from a file. [ File IO, LP]
XPRSreadbinsol	Reads a solution from a binary solution file. [ File IO, Solution]
XPRSreaddirs	Reads a directives file to help direct the tree search. [ Branching, File IO]
XPRSreadprob	Reads an (X)MPS or LP format matrix from file. [ File IO, Problem Creation]
XPRSreadslxsol	Reads an ASCII solution file .slx created by the XPRSwriteslxsol function. [ File IO, Solution]
XPRSrestore	Restores the Optimizer's data structures from a file created by XPRSsave (SAVE). [ File IO, Save Restore]
XPRSsave, XPRSsaveas	Saves the current data structures to file and terminates the run [ File IO, Save Restore]
XPRSsetlogfile	This directs all Optimizer output to a log file. [ File IO, Logging]
XPRStunerreadmethod	This function loads a user defined tuner method from the given file. [ File IO, Tuner]
XPRStunerwritemethod	This function writes the current tuner method to a given file or prints it to the console. [ File IO, Tuner]
XPRSwritebasis	Writes the current basis to a file for later input into the Optimizer. [ File IO, LP]
XPRSwritebinsol	Writes the current MIP or LP solution to a binary solution file for later input into the Optimizer. [ File IO, Solution]
XPRSwritedirs	Writes the tree search directives from the current problem to a directives file. [ Branching, File IO]
XPRSwriteprob	Writes the current problem to an MPS or LP file. [ File IO]
XPRSwriteprtsol	Writes the current solution to a fixed format ASCII file, problem_name .prt. [ File IO, Solution]
XPRSwriteslxsol	Creates an ASCII solution file (.slx) using a similar format to MPS files. These files can be read back into the Optimizer using the XPRSreadslxsol function. [ File IO, Solution]
XPRSwritesol	Writes the current solution to a CSV format ASCII file, problem_name.asc (and .hdr). [ File IO, Solution]

File IO controls

CHECKINPUTDATA	Check input arrays for bad data. [ File IO, Problem Creation]
ESCAPENAMES	If characters illegal to an mps or lp file should be escaped to guarantee readability, and whether escaped characters should be transformed back when reading such a file. [ File IO]
FORCEOUTPUT	Certain names in the problem object may be incompatible with different file formats (such as names containing spaces for LP files). [ File IO]
INPUTTOL	The tolerance on input values elements. [ File IO, Problem Creation, Tolerances]
IOTIMEOUT	The maximum number of seconds to wait for an I/O operation before it is cancelled. [ File IO, Limits]
KEEPNROWS	How nonbinding rows should be handled by the MPS reader. [ File IO, Problem Creation]
MAXTREEFILESIZE	The maximum size, in megabytes, to which the tree file may grow, or 0 for no limit. [ File IO, Limits]
MPS18COMPATIBLE	Provides compatibility of MPS file output for older MPS readers. [ File IO]
MPSBOUNDNAME	When reading an MPS file, this control determines which entries from the BOUNDS section will be read. [ File IO]
MPSECHO	Determines whether comments in MPS matrix files are to be printed out during matrix input. [ File IO]
MPSFORMAT	Specifies the format of MPS files. [ File IO]
MPSOBJNAME	When reading an MPS file, this control determines which neutral row will be read as the objective function. [ File IO]
MPSRANGENAME	When reading an MPS file, this control determines which entries from the RANGES section will be read. [ File IO]
MPSRHSNAME	When reading an MPS file, this control determines which entries from the RHS section will be read. [ File IO]
OUTPUTMASK	Mask to restrict the row and column names written to file. [ File IO]
OUTPUTTOL	Zero tolerance on print values. [ File IO, Tolerances]
TREECOMPRESSION	When writing nodes to the gloal file, the optimizer can try to use data-compression techniques to reduce the size of the tree file on disk. [ Branch and Bound Search, File IO, Memory]
TUNERMETHODFILE	Tuner: Defines a file from which the tuner can read user-defined tuner method. [ File IO, Tuner]
TUNEROUTPUT	Tuner: Whether to output tuner results and logs to the file system. [ File IO, Tuner]
TUNEROUTPUTPATH	Tuner: Defines a root path to which the tuner writes the result file and logs. [ File IO, Tuner]

File IO attributes

RANGENAME	Active range name. [ File IO]
RHSNAME	Active right hand side name. [ File IO]

Global Environment

Reference section for functions, controls, and attributes related to the Global Environment, which acts mainly as a license guard around all Optimizer functionality.

Global Environment library functions

XPRS_ge_addcbmsghandler	Declares an output callback function in the global environment, called every time a line of message text is output by any data in the library. [ Callback, Global Environment]
XPRS_ge_getcomputeallowed	Query whether the current application is allowed to use the Insight Compute interface. [ Compute Interface, Global Environment]
XPRS_ge_getlasterror	Returns the last error encountered during a call to the Xpress global environment. [ Global Environment]
XPRS_ge_removecbmsghandler	Removes a message callback function previously added by XPRS_ge_addcbmsghandler. [ Callback, Global Environment]
XPRS_ge_setarchconsistency	Sets whether to force the same execution path on various CPU architecture extensions, in particular (pre-)AVX and AVX2. [ Global Environment]
XPRS_ge_setcomputeallowed	Set whether the current application is allowed to use the Insight Compute interface. [ Compute Interface, Global Environment]

Global

Reference section for functions, controls, and attributes related to the Global MINLP solver.

Global controls

GLOBALBOUNDINGBOX	If a nonlinear problem cannot be solved due to appearing unbounded, it can automatically be regularized by the application of a bounding box on the variables. [ Global]
GLOBALLSHEURSTRATEGY	When integer-feasible (for MINLP, any solution for NLP) but nonlinear-infeasible solutions are encountered within a global solve, the integer variables can be fixed and a local solver (as defined by the LOCALSOLVER control) can be called on the remaining continuous problem. [ Global, Heuristics]
GLOBALNLPCUTS	Limit on the number of rounds of outer approximation and convexification cuts generated for the root node, when solving an (MI)NLP to global optimality. [ Cuts, Global]
GLOBALNUMINITNLPCUTS	Specifies the maximum number of tangent cuts when setting up the initial relaxation during a global solve. [ Cuts, Global]
GLOBALSPATIALBRANCHCUTTINGEFFORT	Limits the effort that is spent on creating cuts during spatial branching. [ Branching, Global]
GLOBALSPATIALBRANCHIFPREFERORIG	Whether spatial branchings on original variables should be preferred over branching on auxiliary variables that were introduced by the reformulation of the global solver. [ Branching, Global]
GLOBALSPATIALBRANCHPROPAGATIONEFFORT	Limits the effort that is spent on propagation during spatial branching. [ Global, Propagation]
GLOBALTREENLPCUTS	Limit on the number of rounds of outer approximation and convexification cuts generated for each node in the tree, when solving an (MI)NLP to global optimality. [ Cuts, Global]

Global attributes

GLOBALBOUNDINGBOXAPPLIED	Whether a bounding box equal to the absolute value of the GLOBALBOUNDINGBOX control was applied to the problem after the initial solve came back infeasible and if so, to which variables. [ Global]
GLOBALNLPINFEAS	Number of nonlinear infeasibilities at the current node of a global solve, measured as the number of violated atomic formulas. [ Global]

Heuristics

Reference section for functions, controls, and attributes related to Primal Heuristics, which are auxiliary search algorithms for quickly finding improving solutions during the Branch and Bound Search.

Heuristics controls

BACKGROUNDSELECT	Bit-vector control (see Section .) to select which tasks to run in background jobs (for example in parallel to the root cut loop). [ Bit-vector, Heuristics, Root]
FEASIBILITYJUMP	MIP: Decides if the Feasibility Jump heuristic should be run. [ Heuristics]
FEASIBILITYPUMP	Branch and Bound: Decides if the Feasibility Pump heuristic should be run at the root node. [ Heuristics]
GLOBALLSHEURSTRATEGY	When integer-feasible (for MINLP, any solution for NLP) but nonlinear-infeasible solutions are encountered within a global solve, the integer variables can be fixed and a local solver (as defined by the LOCALSOLVER control) can be called on the remaining continuous problem. [ Global, Heuristics]
HEURBEFORELP	Branch and Bound: Determines whether primal heuristics should be run before the initial LP relaxation has been solved. [ Heuristics]
HEURDEPTH	Branch and Bound: Sets the maximum depth in the tree search at which heuristics will be used to find MIP solutions. [ Branch and Bound Search, Heuristics]
HEURDIVEITERLIMIT	Branch and Bound: Simplex iteration limit for reoptimizing during the diving heuristic. [ Heuristics, Limits]
HEURDIVERANDOMIZE	The level of randomization to apply in the diving heuristic. [ Heuristics]
HEURDIVESOFTROUNDING	Branch and Bound: Enables a more cautious strategy for the diving heuristic, where it tries to push binaries and integer variables to their bounds using the objective, instead of directly fixing them. [ Heuristics]
HEURDIVESPEEDUP	Branch and Bound: Changes the emphasis of the diving heuristic from solution quality to diving speed. [ Heuristics]
HEURDIVESTRATEGY	Branch and Bound: Chooses the strategy for the diving heuristic. [ Heuristics]
HEUREMPHASIS	Branch and Bound: This control specifies an emphasis for the search w.r.t. primal heuristics and other procedures that affect the speed of convergence of the primal-dual gap. For problems where the goal is to achieve a small gap but not neccessarily solving them to optimality, it is recommended to set HEUREMPHASIS to 1. This setting triggers many additional heuristic calls, aiming for reducing the gap at the beginning of the search, typically at the expense of an increased time for proving optimality. [ Heuristics]
HEURFORCESPECIALOBJ	Branch and Bound: This specifies whether local search heuristics without objective or with an auxiliary objective should always be used, despite the automatic selection of the Optimiezr. [ Heuristics]
HEURFREQ	Branch and Bound: This specifies the frequency at which heuristics are used in the tree search. [ Branch and Bound Search, Heuristics]
HEURMAXSOL	Branch and Bound: This specifies the maximum number of heuristic solutions that will be found in the tree search. [ Heuristics]
HEURNODES	Branch and Bound: This specifies the maximum number of nodes at which heuristics are used in the tree search. [ Heuristics]
HEURSEARCHBACKGROUNDSELECT	Bit-vector control (see Section .) to select which large neighborhood searches to run in the background (for example in parallel to the root cut loop). [ Bit-vector, Heuristics, Root]
HEURSEARCHCOPYCONTROLS	Select how user-set controls should affect local search heuristics. [ Controls and Attributes, Heuristics]
HEURSEARCHEFFORT	Adjusts the overall level of the local search heuristics. [ Heuristics]
HEURSEARCHFREQ	Branch and Bound: This specifies how often the local search heuristic should be run in the tree. [ Branch and Bound Search, Heuristics]
HEURSEARCHROOTCUTFREQ	How frequently to run the local search heuristic during root cutting. [ Heuristics, Root]
HEURSEARCHROOTSELECT	A bit-vector control (see Section .) for selecting which local search heuristics to apply on the root node of a MIP solve. Use HEURSEARCHTREESELECT to control local search heuristics during the tree search. [ Bit-vector, Heuristics, Root]
HEURSEARCHTREESELECT	A bit-vector control (see Section .) for selecting which local search heuristics to apply during the tree search of a MIP solve. Use HEURSEARCHROOTSELECT to control local search heuristics on the root node. [ Bit-vector, Branch and Bound Search, Heuristics]
HEURSHIFTPROP	Determines whether the Shift-and-propagate primal heuristic should be executed. [ Heuristics]
HEURTHREADS	Branch and Bound: The number of threads to dedicate to running heuristics during the root solve. [ Heuristics, Parallel]
PREROOTEFFORT	Dial for the work spent during the Pre-root parallel heuristic phase. [ Heuristics, Limits, Parallel]
PREROOTTHREADS	Specifies an explicit number of threads that should be used for the Pre-root parallel heuristic phase. [ Heuristics, Memory, Parallel]
PREROOTWORKLIMIT	Set an explicit work limit in work units for the Pre-root parallel heuristic phase. [ Heuristics, Limits, Parallel]
USERSOLHEURISTIC	Determines how much effort to put into running a local search heuristic to find a feasible integer solution from a partial or infeasible user solution. [ Heuristics]

Infeasibility

Reference section for functions, controls, and attributes related to Infeasibility handling. Whenever a problem is infeasible, IIS routines can help to isolate information about the infeasibility. Further API functions help in repairing an infeasibility.

Infeasibility library functions

XPRSgetiisdata	Returns information for an Irreducible Infeasible Set: size, variables and constraints (row and column vectors), and conflicting sides of the variables. [ Infeasibility]
XPRSiisall	Performs an automated search for independent Irreducible Infeasible Sets (IIS) in an infeasible problem. [ Infeasibility]
XPRSiisclear	Resets the search for Irreducible Infeasible Sets (IIS). [ Infeasibility]
XPRSiisfirst	Initiates a search for an Irreducible Infeasible Set (IIS) in an infeasible problem. [ Infeasibility]
XPRSiisisolations	Performs the isolation identification procedure for an Irreducible Infeasible Set (IIS). [ Infeasibility]
XPRSiisnext	Continues the search for further Irreducible Infeasible Sets (IIS), or calls XPRSiisfirst (IIS) if no IIS has been identified yet. [ Infeasibility]
XPRSiisprint	Prints a given Irreducible Infeasible Set (IIS) in the log. [ Infeasibility, Logging]
XPRSiisstatus	Returns statistics on the Irreducible Infeasible Sets (IIS) found so far by XPRSiisfirst (IIS), XPRSiisnext (IIS -n) or XPRSiisall (IIS -a). [ Infeasibility]
XPRSiiswrite	Writes an LP/MPS/CSV file containing a given Irreducible Infeasible Set (IIS). [ File IO, Infeasibility]
XPRSrepairinfeas	Provides a simplified interface for XPRSrepairweightedinfeas. [ Infeasibility]
XPRSrepairweightedinfeas	By relaxing a set of selected constraints and bounds of an infeasible problem, it attempts to identify a 'solution' that violates the selected set of constraints and bounds minimally, while satisfying all other constraints and bounds. [ Infeasibility]
XPRSrepairweightedinfeasbounds	An extended version of XPRSrepairweightedinfeas that allows for bounding the level of relaxation allowed. [ Infeasibility]

Infeasibility console functions

IIS	Console IIS command. [ Infeasibility]
REPAIRINFEAS	An extended version of XPRSrepairweightedinfeas that allows for bounding the level of relaxation allowed. [ Infeasibility]

Infeasibility controls

IISLOG	Selects how much information should be printed during the IIS procedure. [ Infeasibility, Logging]
IISOPS	Selects which part of the restrictions (bounds, constraints, entities) should always be kept in an IIS. [ Bit-vector, Infeasibility]
MAXIIS	This function controls the number of Irreducible Infeasible Sets to be found using the XPRSiisall (IIS -a). [ Infeasibility, Limits]
REPAIRINFEASTIMELIMIT	Overall time limit for the repairinfeas tool [ Infeasibility, Limits]

Infeasibility attributes

IISSOLSTATUS	IIS solution status. [ Infeasibility]
NUMIIS	Number of IISs found. [ Infeasibility]
PENALTYVALUE	The weighted sum of violations in the solution to the relaxed problem identified by the infeasibility repair function. [ Infeasibility]

Licensing

Reference section for functions, controls, and attributes related to Licensing.

Licensing library functions

XPRSfeaturequery	Checks if the provided feature is available in the current license used by the optimizer. [ Licensing]
XPRSfree	Frees any allocated memory and closes all open files. [ Licensing]
XPRSgetdaysleft	Returns the number of days left until the license expires. [ Licensing]
XPRSgetlicerrmsg	Retrieves an error message describing the last licensing error, if any occurred. [ Licensing]
XPRSinit	Initializes the Optimizer library. [ Licensing]

Limits

Reference section for controls and attributes related to the various limits for the solution process.

Limits library functions

XPRSaddcbchecktime	Declares a callback function which is called every time the Optimizer checks if the time limit has been reached. [ Callback, Limits]
XPRSaddcbgapnotify	Declares a gap notification callback, to be called when a MIP solve reaches a predefined target, set using the MIPRELGAPNOTIFY, MIPABSGAPNOTIFY, MIPABSGAPNOTIFYOBJ and/or MIPABSGAPNOTIFYBOUND controls. [ Callback, Limits]
XPRSremovecbchecktime	Removes a callback function previously added by XPRSaddcbchecktime. [ Callback, Limits]
XPRSremovecbgapnotify	Removes a callback function previously added by XPRSaddcbgapnotify. [ Callback, Limits]

Limits controls

BARFAILITERLIMIT	Newton barrier: The maximum number of consecutive iterations that fail to improve the solution in the barrier algorithm. [ Barrier, Limits]
BARINDEFLIMIT	Newton Barrier. [ Barrier, Limits]
BARITERLIMIT	Newton barrier: The maximum number of iterations. [ Barrier, Limits]
HEURDIVEITERLIMIT	Branch and Bound: Simplex iteration limit for reoptimizing during the diving heuristic. [ Heuristics, Limits]
IOTIMEOUT	The maximum number of seconds to wait for an I/O operation before it is cancelled. [ File IO, Limits]
LNPITERLIMIT	Number of iterations to perform in improving each lift-and-project cut. [ Cuts, Limits]
LPITERLIMIT	The maximum number of iterations that will be performed by primal simplex or dual simplex before the optimization process terminates. [ Limits, LP]
MAXCHECKSONMAXCUTTIME	This control is intended for use where optimization runs that are terminated using the MAXCUTTIME control are required to be reproduced exactly. [ Limits]
MAXCHECKSONMAXTIME	This control is intended for use where optimization runs that are terminated using the TIMELIMIT (or the deprecated MAXTIME) control are required to be reproduced exactly. [ Limits]
MAXCUTTIME	The maximum amount of time allowed for generation of cutting planes and reoptimization. [ Cuts, Limits]
MAXIIS	This function controls the number of Irreducible Infeasible Sets to be found using the XPRSiisall (IIS -a). [ Infeasibility, Limits]
MAXMEMORYHARD	This control sets the maximum amount of memory in megabytes the optimizer should allocate. [ Limits, Memory]
MAXMEMORYSOFT	When RESOURCESTRATEGY is enabled, this control sets the maximum amount of memory in megabytes the optimizer targets to allocate. [ Limits, Memory]
MAXMIPSOL	Branch and Bound: This specifies a limit on the number of integer solutions to be found by the Optimizer. [ Limits, Solution]
MAXMIPTASKS	Branch-and-Bound: The maximum number of tasks to run in parallel during a MIP solve. [ Determinism, Limits, Parallel]
MAXNODE	Branch and Bound: The maximum number of nodes that will be explored. [ Branch and Bound Search, Limits]
MAXSTALLTIME	The maximum time in seconds that the Optimizer will continue to search for improving solution after finding a new incumbent. [ Limits]
MAXTREEFILESIZE	The maximum size, in megabytes, to which the tree file may grow, or 0 for no limit. [ File IO, Limits]
MIPABSCUTOFF	Branch and Bound: If the user knows that they are interested only in values of the objective function which are better than some value, this can be assigned to MIPABSCUTOFF. [ Limits]
MIPABSSTOP	Branch and Bound: The absolute tolerance determining whether the tree search will continue or not. [ Limits]
MIPADDCUTOFF	Branch and Bound: The amount to add to the objective function of the best integer solution found to give the new CURRMIPCUTOFF. [ Branch and Bound Search, Limits]
MIPCONCURRENTNODES	Sets the node limit for when a winning solve is selected when concurrent MIP solves are enabled. [ Branch and Bound Search, Limits]
MIPREFINEITERLIMIT	This defines an effort limit expressed as simplex iterations for the MIP solution refiner. [ Limits, Solution Refinement]
MIPRELCUTOFF	Branch and Bound: Percentage of the incumbent value to be added to the value of the objective function when an integer solution is found, to give the new value of CURRMIPCUTOFF. [ Limits]
MIPRELSTOP	Branch and Bound: This determines when the branch and bound tree search will terminate. [ Limits]
MIPTERMINATIONMETHOD	Branch and Bound: How a MIP solve should be stopped on early termination when there are still active tasks in the system. [ Branch and Bound Search, Limits]
NETSTALLLIMIT	Limit the number of degenerate pivots of the network simplex algorithm, before switching to either primal or dual simplex, depending on ALGAFTERNETWORK. [ Limits, Simplex]
PREROOTEFFORT	Dial for the work spent during the Pre-root parallel heuristic phase. [ Heuristics, Limits, Parallel]
PREROOTWORKLIMIT	Set an explicit work limit in work units for the Pre-root parallel heuristic phase. [ Heuristics, Limits, Parallel]
PRESOLVEMAXGROW	Limit on how much the number of non-zero coefficients is allowed to grow during presolve, specified as a ratio of the number of non-zero coefficients in the original problem. [ Limits, Presolve]
PRESOLVEPASSES	Number of reduction rounds to be performed in presolve [ Limits, Presolve]
RELAXTREEMEMORYLIMIT	When the memory used by the branch and bound search tree exceeds the target specified by the TREEMEMORYLIMIT control, the optimizer will try to reduce this by writing nodes to the tree file. [ Limits, Memory]
REPAIRINFEASTIMELIMIT	Overall time limit for the repairinfeas tool [ Infeasibility, Limits]
SBITERLIMIT	Number of dual iterations to perform the strong branching for each entity. [ Branching, Limits]
SOLTIMELIMIT	The maximum time in seconds that the Optimizer will run a MIP solve before it terminates, given that a solution has been found. [ Limits]
TIMELIMIT	The maximum time in seconds that the Optimizer will run before it terminates, including the problem setup time and solution time. [ Limits]
TREEMEMORYLIMIT	A soft limit, in megabytes, for the amount of memory to use in storing the branch and bound search tree. [ Limits, Memory]
TUNERMAXTIME	Tuner: The maximum time in seconds that the tuner will run before it terminates. [ Limits, Tuner]
WORKLIMIT	The maximum work (measured in work units) that the Optimizer will run before it terminates. [ Determinism, Limits]

Limits attributes

CHECKSONMAXCUTTIME	This attribute is used to set the value of the MAXCHECKSONMAXCUTTIME control. [ Limits]
CHECKSONMAXTIME	This attribute is used to set the value of the MAXCHECKSONMAXTIME control. [ Limits]

Linear Algebra

Reference section for functions, controls, and attributes related to Linear Algebra routines.

Linear Algebra library functions

XPRSbasisstability	Calculates various measures for the stability of the current basis, including the basis condition number. [ Linear Algebra, LP]
XPRSbtran	Post-multiplies a (row) vector provided by the user by the inverse of the current basis. [ Linear Algebra, LP]
XPRScalcreducedcosts	Calculates the reduced cost values for a given (row) dual solution. [ Linear Algebra, Solution]
XPRSftran	Pre-multiplies a (column) vector provided by the user by the inverse of the current matrix. [ Linear Algebra, LP]
XPRSgetbasis	Returns the current basis into the user's data arrays. [ Linear Algebra, LP]
XPRSgetbasisval	Returns the current basis status for a specific column or row. [ Linear Algebra, LP]
XPRSgetredcosts	Returns the reduced costs reduced cost for this variable from the incumbent solution during or after optimization of a continuous problem with XPRSoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ Linear Algebra, LP]
XPRSpivot	Performs a simplex pivot by bringing variable enter into the basis and removing leave. [ Linear Algebra, Simplex]
XPRSsparsebtran	Post-multiplies a (row) vector provided by the user by the inverse of the current matrix. [ Linear Algebra, Simplex]
XPRSsparseftran	Pre-multiplies a (column) vector provided by the user by the inverse of the current matrix. [ Linear Algebra, Simplex]

Linear Algebra console functions

CHECKCONVEXITY	Convexity checker. [ Linear Algebra, Quadratic]
BASISSTABILITY	Calculates various measures for the stability of the current basis, including the basis condition number. [ Linear Algebra, LP]

Logging

Reference section for functions, controls, and attributes related to Logging.

Logging library functions

XPRSaddcbcutlog	Declares a cut log callback function, called each time the cut log is printed. [ Callback, Logging]
XPRSaddcbmessage	Declares an output callback function, called every time a text line relating to the given XPRSprob is output by the Optimizer. [ Callback, Logging]
XPRSaddcbmiplog	Declares a MIP log callback function, called each time the MIP log is printed. [ Callback, Logging]
XPRSiisprint	Prints a given Irreducible Infeasible Set (IIS) in the log. [ Infeasibility, Logging]
XPRSremovecbcutlog	Removes a cut log callback function previously added by XPRSaddcbcutlog. [ Callback, Logging]
XPRSremovecblplog	Removes a simplex log callback function previously added by XPRSaddcblplog. [ Callback, Logging]
XPRSremovecbmessage	Removes a message callback function previously added by XPRSaddcbmessage. [ Callback, Logging]
XPRSremovecbmiplog	Removes a MIP log callback function previously added by XPRSaddcbmiplog. [ Callback, Logging]
XPRSsetlogfile	This directs all Optimizer output to a log file. [ File IO, Logging]

Logging controls

BAROUTPUT	Newton barrier and hybrid gradient: This specifies the level of solution output provided. [ Barrier, Logging, Primal Dual Hybrid Gradient]
IISLOG	Selects how much information should be printed during the IIS procedure. [ Infeasibility, Logging]
LPLOG	Simplex: The frequency at which the simplex log is printed. [ Logging, LP]
LPLOGDELAY	Time interval between two LP log lines. [ Logging, LP]
LPLOGSTYLE	Simplex: The style of the simplex log. [ Logging, LP]
MAXPAGELINES	Number of lines between page breaks in printable output. [ Logging]
MIPLOG	MIP log print control. [ Logging]
MULTIOBJLOG	Log level for multi-objective optimization. [ Logging, Multiobjective]
OUTPUTCONTROLS	This control toggles the printing of all control settings at the beginning of the search. [ Logging]
OUTPUTLOG	This controls the level of output produced by the Optimizer during optimization. [ Logging]
TRACE	Display the infeasibility diagnosis during presolve. [ Logging, Presolve]
TREEDIAGNOSTICS	A bit-vector (see Section .) providing control over how various tree-management-related messages get printed in the tree log file during the branch-and-bound search. [ Bit-vector, Branch and Bound Search, Logging]
TREEFILELOGINTERVAL	This control sets the interval between progress messages output while writing tree data to the tree file, in seconds. [ Branch and Bound Search, Logging]
TUNERVERBOSE	Tuner: whether the tuner should prints detailed information for each run. [ Logging, Tuner]

LP

Reference section for functions, controls, and attributes related to the LP algorithms of the Optimizer. Note that many of them will affect both standalone LP optimization problems, as well as the various LP relaxations that are solved during a Branch and Bound Search.

LP library functions

XPRSaddcblplog	Declares a simplex log callback function which is called after every LPLOG iterations of the simplex algorithm. [ Callback, LP]
XPRSbasisstability	Calculates various measures for the stability of the current basis, including the basis condition number. [ Linear Algebra, LP]
XPRSbndsa	Returns upper and lower sensitivity ranges for specified variables' lower and upper bounds. [ LP, Sensitivity Analysis]
XPRSbtran	Post-multiplies a (row) vector provided by the user by the inverse of the current basis. [ Linear Algebra, LP]
XPRScrossoverlpsol	Provides a basic optimal solution for a given solution of an LP problem. [ Barrier, LP]
XPRSestimaterowdualranges	Performs a dual side range sensitivity analysis, i.e. calculates estimates for the possible ranges for dual values. [ LP, Sensitivity Analysis]
XPRSftran	Pre-multiplies a (column) vector provided by the user by the inverse of the current matrix. [ Linear Algebra, LP]
XPRSgetbasis	Returns the current basis into the user's data arrays. [ Linear Algebra, LP]
XPRSgetbasisval	Returns the current basis status for a specific column or row. [ Linear Algebra, LP]
XPRSgetdualray	Retrieves a dual ray (dual unbounded direction) for the current problem, if the problem is found to be infeasible. [ LP, Solution]
XPRSgetduals	Returns the dual values dual value for this constraint from the incumbent solution during or after optimization of a continuous problem with XPRSoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ LP, Solution]
XPRSgetinfeas	Returns a list of infeasible primal and dual variables. [ LP, Solution]
XPRSgetlpsol	Used to obtain the LP solution values following optimization. [ LP, Solution]
XPRSgetpivotorder	Returns the pivot order of the basic variables. [ LP, Simplex]
XPRSgetpivots	Returns a list of potential leaving variables if a specified variable enters the basis. [ LP, Simplex]
XPRSgetpresolvebasis	Returns the current basis from memory into the user's data areas. [ LP, Simplex]
XPRSgetprimalray	Retrieves a primal ray (primal unbounded direction) for the current problem, if the problem is found to be unbounded. [ LP, Solution]
XPRSgetredcosts	Returns the reduced costs reduced cost for this variable from the incumbent solution during or after optimization of a continuous problem with XPRSoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ Linear Algebra, LP]
XPRSgetscaledinfeas	Returns a list of scaled infeasible primal and dual variables for the original problem. [ LP, Numerics]
XPRSgetslacks	Returns the slack values slack value for this constraint from the incumbent solution during or after optimization with XPRSoptimize, XPRSmipoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ LP, Solution]
XPRSgetunbvec	Returns the index vector which causes the primal simplex or dual simplex algorithm to determine that a matrix is primal or dual unbounded respectively. [ LP, Solution]
XPRSloadbasis	Loads a basis from the user's areas. [ Data Input, LP]
XPRSloadlp, XPRSloadlp64	Enables the user to pass a matrix directly to the Optimizer, rather than reading the matrix from a file. [ LP, Problem Input]
XPRSloadlpsol	Loads an LP solution for the problem into the Optimizer. [ Data Input, LP, Solution]
XPRSloadpresolvebasis	Loads a presolved basis from the user's areas. [ Data Input, LP]
XPRSlpoptimize	This function begins a search for the optimal continuous (LP) solution. [ LP, Solution Process]
XPRSobjsa	Returns upper and lower sensitivity ranges for specified objective function coefficients. [ LP, Sensitivity Analysis]
XPRSreadbasis	Instructs the Optimizer to read in a previously saved basis from a file. [ File IO, LP]
XPRSrhssa	Returns upper and lower sensitivity ranges for specified right hand side (RHS) function coefficients. [ LP, Sensitivity Analysis]
XPRSwritebasis	Writes the current basis to a file for later input into the Optimizer. [ File IO, LP]

LP controls

ALGAFTERCROSSOVER	The algorithm to be used for the final clean up step after the crossover. [ Barrier, LP]
ALGAFTERNETWORK	The algorithm to be used for the clean up step after the network simplex solver. [ LP, Simplex]
AUTOPERTURB	Simplex: This indicates whether automatic perturbation is performed. [ LP]
BARALG	This control determines which barrier algorithm is used to solve the problem. [ Barrier, LP, Primal Dual Hybrid Gradient]
BIGM	The infeasibility penalty used if the "Big M" method is implemented. [ LP, Numerics]
BIGMMETHOD	Simplex: This specifies whether to use the "Big M" method, or the standard phase I (achieving feasibility) and phase II (achieving optimality). [ LP, Numerics]
CONCURRENTTHREADS	Determines the number of threads used by the concurrent solver. [ LP, Parallel]
CRASH	Simplex: This determines the type of crash used when the algorithm begins. [ Bit-vector, LP, Simplex]
DEFAULTALG	This selects the algorithm that will be used to solve LPs, standalone or during MIP optimization. [ Branch and Bound Search, LP]
DENSECOLLIMIT	Newton barrier: Columns with more than DENSECOLLIMIT elements are considered to be dense. [ Barrier, LP]
DUALGRADIENT	Simplex: This specifies the dual simplex pricing method. [ LP, Simplex]
DUALIZE	For a linear problem or the initial linear relaxation of a MIP, determines whether to form and solve the dual problem. [ LP, Problem Transformation]
DUALIZEOPS	Bit-vector control (see Section .) for adjusting the behavior when a problem is dualized. [ Bit-vector, LP]
DUALPERTURB	The factor by which the problem will be perturbed prior to optimization by dual simplex. [ LP, Simplex]
DUALSTRATEGY	This bit-vector control (see Section .) specifies the dual simplex strategy. [ Bit-vector, LP, Simplex]
DUALTHREADS	Determines the maximum number of threads that dual simplex is allowed to use. [ LP, Parallel]
FORCEPARALLELDUAL	Dual simplex: specifies whether the dual simplex solver should always use the parallel simplex algorithm. [ LP, Simplex]
KEEPBASIS	Simplex: This determines whether the basis should be kept when reoptimizing a problem. [ LP, Simplex]
LPFLAGS	A bit-vector control (see Section .) which defines the algorithm for solving an LP problem or the initial LP relaxation of a MIP problem. [ Bit-vector, LP, Root]
LPFOLDING	Simplex and barrier: whether to fold an LP problem before solving it. [ LP]
LPITERLIMIT	The maximum number of iterations that will be performed by primal simplex or dual simplex before the optimization process terminates. [ Limits, LP]
LPLOG	Simplex: The frequency at which the simplex log is printed. [ Logging, LP]
LPLOGDELAY	Time interval between two LP log lines. [ Logging, LP]
LPLOGSTYLE	Simplex: The style of the simplex log. [ Logging, LP]
LPREFINEITERLIMIT	This specifies the simplex iteration limit the solution refiner can spend in attempting to increase the accuracy of an LP solution. [ LP, Solution Refinement]
MARKOWITZTOL	The Markowitz tolerance used for the factorization of the basis matrix. [ LP, Simplex]
PREPROTECTDUAL	Presolve: specifies whether the presolver should protect a given dual solution by maintaining the same level of dual feasibility. [ LP, Presolve]
PRICINGALG	Simplex: This determines the primal simplex pricing method. [ LP, Simplex]
PRIMALOPS	Primal simplex: allows fine tuning the variable selection in the primal simplex solver. [ Bit-vector, LP, Simplex]
PRIMALPERTURB	The factor by which the problem will be perturbed prior to optimization by primal simplex. [ LP, Simplex]
PRIMALUNSHIFT	Determines whether primal is allowed to call dual to unshift. [ LP, Simplex]
SIFTING	Determines whether to enable sifting algorithm with the dual simplex method. [ LP, Simplex]
SIFTPASSES	Determines how quickly we allow to grow the worker problems during the sifting algorithm. [ LP, Simplex]
SIFTPRESOLVEOPS	Determines the presolve operations for solving the subproblems during the sifting algorithm. [ LP, Simplex]
SIFTSWITCH	Determines which algorithm to use for solving the subproblems during sifting. [ LP, Simplex]

LP attributes

ALGORITHM	The algorithm the optimizer currently is running / was running just before completition. [ LP]
CROSSOVERITER	Number of simplex iterations performed in crossover. [ Barrier, LP]
DUALINFEAS	Number of dual infeasibilities. [ LP]
LPOBJVAL	Value of the objective function of the last LP solved. [ LP]
LPSTATUS	LP solution status. [ LP]
MAXABSDUALINFEAS	Maximum calculated absolute dual infeasibility in the unscaled original problem. [ LP, Numerics]
MAXABSPRIMALINFEAS	Maximum calculated absolute primal infeasibility in the unscaled original problem. [ LP, Numerics]
MAXRELDUALINFEAS	Maximum calculated relative dual infeasibility in the unscaled original problem. [ LP, Numerics]
MAXRELPRIMALINFEAS	Maximum calculated relative primal infeasibility in the unscaled original problem. [ LP, Numerics]
PRIMALINFEAS	Number of primal infeasibilities. [ LP]
SIMPLEXITER	Number of simplex iterations performed. [ LP, Simplex]
SUMPRIMALINF	Scaled sum of primal infeasibilities. [ LP, Numerics]

Memory

Reference section for functions, controls, and attributes related to memory handling and usage.

Memory controls

MAXMEMORYHARD	This control sets the maximum amount of memory in megabytes the optimizer should allocate. [ Limits, Memory]
MAXMEMORYSOFT	When RESOURCESTRATEGY is enabled, this control sets the maximum amount of memory in megabytes the optimizer targets to allocate. [ Limits, Memory]
PREROOTTHREADS	Specifies an explicit number of threads that should be used for the Pre-root parallel heuristic phase. [ Heuristics, Memory, Parallel]
RELAXTREEMEMORYLIMIT	When the memory used by the branch and bound search tree exceeds the target specified by the TREEMEMORYLIMIT control, the optimizer will try to reduce this by writing nodes to the tree file. [ Limits, Memory]
RESOURCESTRATEGY	Controls whether the optimizer is allowed to make nondeterministic decisions if memory is running low in an effort to preserve memory and finish the solve. [ Determinism, Memory]
TREECOMPRESSION	When writing nodes to the gloal file, the optimizer can try to use data-compression techniques to reduce the size of the tree file on disk. [ Branch and Bound Search, File IO, Memory]
TREEMEMORYLIMIT	A soft limit, in megabytes, for the amount of memory to use in storing the branch and bound search tree. [ Limits, Memory]
TREEMEMORYSAVINGTARGET	When the memory used by the branch-and-bound search tree exceeds the limit specified by the TREEMEMORYLIMIT control, the optimizer will try to save memory by writing lower-rated sections of the tree to the tree file. [ Branch and Bound Search, Memory]

Memory attributes

AVAILABLEMEMORY	The amount of heap memory detected by Xpress as free. [ Memory]
CURRENTMEMORY	The amount of dynamically allocated heap memory by the problem being solved. [ Memory]
MEMORYLIMITDETECTED	The detected amount of memory accessible to the solver process, in megabytes. [ Memory]
PEAKMEMORY	An estimate of the peak amount of dynamically allocated heap memory by the problem. [ Memory]
PEAKTOTALTREEMEMORYUSAGE	The peak size, in megabytes, that the branch-and-bound search tree reached during the solve. [ Branch and Bound Search, Memory]
SYSTEMMEMORY	The amount of non problem specific memory used by the solver. [ Memory, System]
TOTALMEMORY	The amount of dynamically allocated heap memory by the optimizer, including all problems currently exsisting. [ Memory]
TREEFILESIZE	The allocated size of the tree file, in megabytes. [ Branch and Bound Search, Memory]
TREEFILEUSAGE	The number of megabytes of data from the branch-and-bound tree that have been saved to the tree file. [ Branch and Bound Search, Memory]
TREEMEMORYUSAGE	The amount of physical memory, in megabytes, currently being used to store the branch-and-bound search tree. [ Branch and Bound Search, Memory]

MIP Entities

Reference section for functions, controls, and attributes related to MIP Entities, such as binary and integer variables. Further MIP entity column types comprise semi-continuous, semi-integer, partial integer variables. Special Ordered Sets of type I and II are also MIP entities.

MIP Entities library functions

XPRSaddsets, XPRSaddsets64	Allows sets to be added to the problem after passing it to the Optimizer using the input routines. [ MIP Entities, Problem Creation]
XPRSchgcoltype	Used to change the type of a specified set of columns in the matrix. [ MIP Entities, Problem Modification]
XPRSchgglblimit	Used to change semi-continuous or semi-integer lower bounds, or upper limits on partial integers. [ MIP Entities, Problem Modification]
XPRSdelindicators	Delete indicator constraints. [ MIP Entities, Problem Creation]
XPRSdelsets	Delete sets from a problem. [ MIP Entities, Problem Creation]
XPRSfixmipentities	Fixes all the MIP entities to the values of the last found MIP solution. [ MIP Entities, Problem Modification]
XPRSgetcoltype	Returns the column types for the columns in a given range. [ MIP Entities, Problem Information]
XPRSgetmipentities, XPRSgetmipentities64	Retrieves integr and entity information about a problem. [ MIP Entities, Problem Information]
XPRSloadmip, XPRSloadmip64	Used to load a MIP problem into the Optimizer data structures. [ MIP Entities, Problem Input]
XPRSloadmipsol	Loads a starting MIP solution for the problem into the Optimizer. [ Data Input, MIP Entities, Solution]
XPRSmipoptimize	This function begins a tree search for the optimal MIP solution. [ MIP Entities, Solution Process]

MIP Entities attributes

INDICATORS	Number of indicator constrains in the problem. [ MIP Entities, Problem Information]
MAXMIPINFEAS	Maximum integer fractionality in the solution. [ MIP Entities, Numerics]
MIPENTS	Number of MIP entities (i.e. binary, integer, semi-continuous, partial integer, and semi-continuous integer variables) but excluding the number of special ordered sets. [ MIP Entities, Problem Information]
MIPINFEAS	Number of integer infeasibilities, including violations of special ordered sets, at the current node. [ Branch and Bound Search, MIP Entities]
ORIGINALINDICATORS	Number of indicator constraints in the original matrix before presolving. [ MIP Entities, Problem Information]
ORIGINALMIPENTS	Number of MIP entities (i.e. binary, integer, semi-continuous, partial integer, and semi-continuous integer variables) but excluding the number of special ordered sets in the original matrix before presolving. [ MIP Entities, Problem Information]
ORIGINALSETMEMBERS	Number of variables within special ordered sets (set members) in the original matrix before presolving. [ MIP Entities, Problem Information]
ORIGINALSETS	Number of special ordered sets in the original matrix before presolving. [ MIP Entities, Problem Information]
SETMEMBERS	Number of variables within special ordered sets (set members) in the matrix. [ MIP Entities, Problem Information]
SETS	Number of special ordered sets in the matrix. [ MIP Entities, Problem Information]
SPAREMIPENTS	Number of spare MIP entities in the matrix. [ MIP Entities, Problem Information]
SPARESETELEMS	Number of spare set elements in the matrix. [ MIP Entities, Problem Information]
SPARESETS	Number of spare sets in the matrix. [ MIP Entities, Problem Information]

Misc

Reference section for further miscellaneous functionality of the Optimizer.

Misc library functions

XPRSgetbanner	Returns the banner and copyright message. [ Misc]
XPRSgetcheckedmode	You can use this function to interrogate whether checking and validation of all Optimizer function calls is enabled for the current process. [ Misc]
XPRSgetlasterror	Returns the error message corresponding to the last error encountered by a library function. [ Misc]
XPRSgetmessagestatus	Retrieves the current suppression status of a message. [ Misc]
XPRSgetversion	Returns the full Optimizer version number in the form 15.10.03, where 15 is the major release, 10 is the minor release, and 03 is the build number. [ Misc]
XPRSgetversionnumbers	Returns the Optimizer version numbers split into major, minor, and build number. [ Misc]
XPRSpresolverow	Presolves a row formulated in terms of the original variables such that it can be added to a presolved matrix. [ Misc, Presolve]
XPRSsetcheckedmode	You can use this function to disable some of the checking and validation of function calls and function call parameters for calls to the Xpress Optimizer API. [ Misc]
XPRSsetmessagestatus	Manages suppression of messages. [ Misc]

Misc console functions

EXIT	Terminate the Console Optimizer. [ Misc]
HELP	Quick reference help for the Optimizer console. [ Misc]
QUIT	Terminate the Console Optimizer. [ Misc]
STOP	Terminate the Console Optimizer. [ Misc]

Misc controls

CPIALPHA	decay term for confined primal integral computation. [ Misc]
VERSION	The Optimizer version number, e.g. 1301 meaning release 13.01. [ Misc]

Misc attributes

BOUNDNAME	Active bound name. [ Misc]
CPISCALEFACTOR	scale factor from primal integral computation. [ Misc]
ERRORCODE	The most recent Optimizer error number that occurred. [ Misc]
MAXPROBNAMELENGTH	Maximum size of the problem name and also the maximum allowed length of the file or path string for any function that accepts such an argument (not including the NULL terminator). [ Misc]
NAMELENGTH	The length (in 8 character units) of row and column names in the matrix. [ Misc]
PRIMALDUALINTEGRAL	Value of the primal-dual integral. [ Misc]
UUID	Universally Unique Identifier for the problem instance. [ Misc]
XPRESSVERSION	The Xpress version number. [ Misc]

Multiobjective

Reference section for functions, controls, and attributes for solving multiobjective problems.

Multiobjective library functions

XPRSaddcbafterobjective	Declares a callback which will be called after each objective in a multi-objective problem is solved. [ Callback, Multiobjective]
XPRSaddcbbeforeobjective	Declares a callback which will be called before each objective in a multi-objective problem is solved. [ Callback, Multiobjective]
XPRSaddobj	Appends an objective function with the given coefficients to a multi-objective problem. [ Multiobjective, Problem Creation]
XPRScalcobjn	Calculates the objective value of the given objective function in a multi-objective problem. [ Multiobjective, Solution]
XPRSchgobjn	Modifies one or more coefficients of an objective function in a multi-objective problem. [ Multiobjective, Problem Modification]
XPRSgetobjdblattrib	Retrieves the value of a given double attribute associated with a multi-objective solve. [ Controls and Attributes, Multiobjective]
XPRSgetobjdblcontrol	Retrieves the value of a given double control parameter associated with an objective function. [ Controls and Attributes, Multiobjective]
XPRSgetobjecttypename	Function to access the type name of an object referenced using the generic Optimizer object pointer XPRSobject. [ Controls and Attributes, Multiobjective]
XPRSgetobjintattrib, XPRSgetobjintattrib64	Retrieves the value of a given integer attribute associated with a multi-objective solve. [ Controls and Attributes, Multiobjective]
XPRSgetobjintcontrol	Retrieves the value of a given integer control parameter associated with an objective. [ Controls and Attributes, Multiobjective]
XPRSgetobjn	For a given objective function, returns the objective coefficients for the columns in a given range. [ Multiobjective, Problem Information]
XPRSremovecbafterobjective	Removes a callback function previously added by XPRSaddcbafterobjective. [ Callback, Multiobjective]
XPRSremovecbbeforeobjective	Removes a callback function previously added by XPRSaddcbbeforeobjective. [ Callback, Multiobjective]
XPRSsetobjdblcontrol	Sets the value of a given double control parameter associated with an objective. [ Controls and Attributes, Multiobjective]
XPRSsetobjintcontrol	Sets the value of a given integer control parameter associated with an objective. [ Controls and Attributes, Multiobjective]

Multiobjective controls

MULTIOBJLOG	Log level for multi-objective optimization. [ Logging, Multiobjective]
MULTIOBJOPS	Modifies the behaviour of the optimizer when solving multi-objective problems. [ Bit-vector, Multiobjective]

Multiobjective attributes

OBJECTIVES	Number of objectives in the problem. [ Multiobjective]
OBJSTOSOLVE	Number of objectives that will be solved during the current multi-objective solve. [ Multiobjective]
SOLVEDOBJS	Number of objectives that have been solved so far during a multi-objective solve. [ Multiobjective]

Names Manager

Reference section for functions, controls, and attributes related to the Names Manager.

Names Manager library functions

XPRSgetnamelist

Returns the names for the rows, columns, sets, piecewise linear constraints, general constraints or objectives in a given range.
[ Names Manager]

Numerics

Reference section for functions, controls, and attributes related to Numerics.

Numerics library functions

XPRSgetscale	Returns the the current scaling of the matrix. [ Numerics]
XPRSgetscaledinfeas	Returns a list of scaled infeasible primal and dual variables for the original problem. [ LP, Numerics]
XPRSscale	Re-scales the current matrix. [ Numerics]

Numerics controls

AUTOSCALING	Whether the Optimizer should automatically select between different scaling algorithms. [ Numerics, Problem Transformation]
BAROBJSCALE	Defines how the barrier scales the objective. [ Barrier, Numerics]
BARPERTURB	Newton barrier: In numerically challenging cases it is often advantageous to apply perturbations on the KKT system to improve its numerical properties. [ Barrier, Numerics]
BARRHSSCALE	Defines how the barrier scales the right hand side. [ Barrier, Numerics]
BIGM	The infeasibility penalty used if the "Big M" method is implemented. [ LP, Numerics]
BIGMMETHOD	Simplex: This specifies whether to use the "Big M" method, or the standard phase I (achieving feasibility) and phase II (achieving optimality). [ LP, Numerics]
CLAMPING	This bit-vector control (see Section .) allows for the adjustment of returned solution values such that they are always within bounds. [ Bit-vector, Numerics, Solution]
MAXIMPLIEDBOUND	Presolve: When tighter bounds are calculated during MIP preprocessing, only bounds whose absolute value are smaller than MAXIMPLIEDBOUND will be applied to the problem. [ Numerics, Presolve]
MAXSCALEFACTOR	This determines the maximum scaling factor that can be applied during scaling. [ Numerics, Presolve]
MIPKAPPAFREQ	Branch and Bound: Specifies how frequently the basis condition number (also known as kappa) should be calculated during the branch-and-bound search. [ Branch and Bound Search, Numerics]
NUMERICALEMPHASIS	How much emphasis to place on numerical stability instead of solve speed. [ Numerics]
OBJSCALEFACTOR	Custom objective scaling factor, expressed as a power of 2. [ Numerics]
SCALING	This bit-vector control (see Section .) determines how the Optimizer will rescale a model internally before optimization. If set to 0, no scaling will take place. [ Bit-vector, Numerics, Problem Transformation]

Numerics attributes

ATTENTIONLEVEL	A measure between 0 and 1 for how numerically unstable the problem is. [ Branch and Bound Search, Numerics]
MAXABSDUALINFEAS	Maximum calculated absolute dual infeasibility in the unscaled original problem. [ LP, Numerics]
MAXABSPRIMALINFEAS	Maximum calculated absolute primal infeasibility in the unscaled original problem. [ LP, Numerics]
MAXKAPPA	Largest basis condition number (also known as kappa) calculated through all nodes sampled by MIPKAPPAFREQ. [ Branch and Bound Search, Numerics]
MAXMIPINFEAS	Maximum integer fractionality in the solution. [ MIP Entities, Numerics]
MAXRELDUALINFEAS	Maximum calculated relative dual infeasibility in the unscaled original problem. [ LP, Numerics]
MAXRELPRIMALINFEAS	Maximum calculated relative primal infeasibility in the unscaled original problem. [ LP, Numerics]
PREDICTEDATTLEVEL	A measure between 0 and 1 to predict how numerically unstable the current MIP solve can be expected to be. [ Numerics]
SUMPRIMALINF	Scaled sum of primal infeasibilities. [ LP, Numerics]

Parallel

Reference section for functionality how the Optimizer takes advantage of modern multi-core CPUs. By default, the Optimizer will detect how many cores are available in the system and try to use all of them. The controls in this section affect to which extent the Optimizer uses the parallel hardware.

Parallel library functions

XPRSaddcbdestroymt	Declares a destroy MIP thread callback function, called every time a MIP thread is destroyed by the parallel MIP code. [ Callback, Parallel]
XPRSaddcbmipthread	Declares a MIP thread callback function, called every time a MIP worker problem is created by the parallel MIP code. [ Callback, Parallel]
XPRSremovecbdestroymt	Removes a slave thread destruction callback function previously added by XPRSaddcbdestroymt. [ Callback, Parallel]
XPRSremovecbmipthread	Removes a callback function previously added by XPRSaddcbmipthread. [ Callback, Parallel]

Parallel controls

BACKGROUNDMAXTHREADS	Limit the number of threads to use in background jobs (for example in parallel to the root cut loop). [ Parallel, Root]
BARCORES	If set to a positive integer it determines the number of physical CPU cores assumed to be present in the system by the barrier and hybrid gradient algorithms. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
BARORDERTHREADS	If set to a positive integer it determines the number of concurrent threads for the sparse matrix ordering algorithm in the Newton-barrier method. [ Barrier, Parallel]
BARTHREADS	If set to a positive integer it determines the number of threads implemented to run the Newton-barrier and hybrid gradient algorithms. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
CONCURRENTTHREADS	Determines the number of threads used by the concurrent solver. [ LP, Parallel]
CROSSOVERTHREADS	Determines the maximum number of threads that parallel crossover is allowed to use. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
DUALTHREADS	Determines the maximum number of threads that dual simplex is allowed to use. [ LP, Parallel]
HEURTHREADS	Branch and Bound: The number of threads to dedicate to running heuristics during the root solve. [ Heuristics, Parallel]
MAXMIPTASKS	Branch-and-Bound: The maximum number of tasks to run in parallel during a MIP solve. [ Determinism, Limits, Parallel]
MIPTHREADS	If set to a positive integer it determines the number of threads implemented to run the parallel MIP code. [ Branch and Bound Search, Parallel]
PREROOTEFFORT	Dial for the work spent during the Pre-root parallel heuristic phase. [ Heuristics, Limits, Parallel]
PREROOTTHREADS	Specifies an explicit number of threads that should be used for the Pre-root parallel heuristic phase. [ Heuristics, Memory, Parallel]
PREROOTWORKLIMIT	Set an explicit work limit in work units for the Pre-root parallel heuristic phase. [ Heuristics, Limits, Parallel]
THREADS	The default number of threads used during optimization. [ Parallel]
TUNERTHREADS	Tuner: the number of threads used by the tuner. [ Parallel, Tuner]

Piecewise Linear and General Constraints

Reference section for functions, controls, and attributes related to Piecewise Linear and General Constraints.

Piecewise Linear and General Constraints library functions

XPRSaddgencons, XPRSaddgencons64	Adds one or more general constraints to the problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSaddpwlcons, XPRSaddpwlcons64	Adds one or more piecewise linear constraints to the problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSdelgencons	Delete general constraints from a problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSdelpwlcons	Delete piecewise linear constraints from a problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSgetgencons, XPRSgetgencons64	Returns the general constraints y = f(x1, ..., xn, c1, ..., cm) in a given range. [ Piecewise Linear and General Constraints, Problem Information]
XPRSgetpwlcons, XPRSgetpwlcons64	Returns the piecewise linear constraints y = f(x) in a given range. [ Piecewise Linear and General Constraints, Problem Information]

Piecewise Linear and General Constraints controls

GENCONSABSTRANSFORMATION	This control specifies the reformulation method for absolute value general constraints at the beginning of the search. [ Piecewise Linear and General Constraints, Presolve]
GENCONSDUALREDUCTIONS	This parameter specifies whether dual reductions should be applied to reduce the number of columns and rows added when transforming general constraints to MIP structs. [ Piecewise Linear and General Constraints, Presolve]
PWLDUALREDUCTIONS	This parameter specifies whether dual reductions should be applied to reduce the number of columns, rows and SOS-constraints added when transforming piecewise linear objectives and constraints to MIP structs. [ Piecewise Linear and General Constraints, Presolve, Problem Transformation]
PWLNONCONVEXTRANSFORMATION	This control specifies the reformulation method for piecewise linear constraints at the beginning of the search. [ Piecewise Linear and General Constraints, Presolve, Problem Transformation]

Piecewise Linear and General Constraints attributes

GENCONCOLS	Number of input variables in general constraints (i.e. MIN/MAX/AND/OR/ABS constraints) in the problem. [ Piecewise Linear and General Constraints, Problem Information]
GENCONS	The number of general constraints (i.e. MIN/MAX/AND/OR/ABS constraints) in the problem. [ Piecewise Linear and General Constraints, Problem Information]
GENCONVALS	Number of constant values in general constraints (MIN/MAX constraints) in the problem. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALGENCONCOLS	Number of input variables in general constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALGENCONS	Number of general constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALGENCONVALS	Number of constant values in general constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALPWLPOINTS	Number of breakpoints of piecewise linear constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALPWLS	Number of piecewise linear constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
PWLCONS	Number of piecewise linear constraints in the problem. [ Piecewise Linear and General Constraints, Problem Information]
PWLPOINTS	Number of breakpoints of piecewise linear constraints in the problem. [ Piecewise Linear and General Constraints, Problem Information]

Presolve

Reference section for functions, controls, and attributes related to Presolve. Presolve is a collection of techniques to transform the input problem into an equivalent, but smaller problem by fixing or eliminating columns and rows.

Presolve library functions

XPRSaddcbpresolve	Declares a callback to be called after presolve has been performed. [ Callback, Presolve]
XPRSgetpresolvemap	Returns the mapping of the row and column numbers from the presolve problem back to the original problem. [ Presolve, Problem Information]
XPRSgetpresolvesol	Returns the solution for the presolved problem from memory. [ Presolve, Solution]
XPRSloadsecurevecs	Allows the user to mark rows and columns in order to prevent the presolve removing these rows and columns from the matrix. [ Data Input, Presolve]
XPRSpostsolve	Postsolve the current matrix when it is in a presolved state. [ Presolve, Solution Process]
XPRSpostsolvesol	Postsolves a primal solution formulated in the presolved space into the corresponding solution formulated in the original space. [ Presolve, Solution]
XPRSpresolverow	Presolves a row formulated in terms of the original variables such that it can be added to a presolved matrix. [ Misc, Presolve]
XPRSremovecbpresolve	Removes a presolve callback function previously added by XPRSaddcbpresolve. [ Callback, Presolve]

Presolve controls

BARPRESOLVEOPS	Newton barrier: This bit-vector (see Section .) controls the Newton-Barrier specific presolve operations. [ Barrier, Bit-vector, Presolve]
ELIMFILLIN	Amount of fill-in allowed when performing an elimination in presolve . [ Presolve]
ELIMTOL	The Markowitz tolerance for the elimination phase of the presolve. [ Presolve, Tolerances]
GENCONSABSTRANSFORMATION	This control specifies the reformulation method for absolute value general constraints at the beginning of the search. [ Piecewise Linear and General Constraints, Presolve]
GENCONSDUALREDUCTIONS	This parameter specifies whether dual reductions should be applied to reduce the number of columns and rows added when transforming general constraints to MIP structs. [ Piecewise Linear and General Constraints, Presolve]
IFCHECKCONVEXITY	Determines if the convexity of the problem is checked before optimization. [ Presolve, Quadratic]
INDLINBIGM	During presolve, indicator constraints will be linearized using a BigM coefficient whenever that BigM coefficient is small enough. [ Presolve, Problem Transformation]
INDPRELINBIGM	During presolve, indicator constraints will be linearized using a BigM coefficient whenever that BigM coefficient is small enough. [ Presolve, Problem Transformation]
MAXIMPLIEDBOUND	Presolve: When tighter bounds are calculated during MIP preprocessing, only bounds whose absolute value are smaller than MAXIMPLIEDBOUND will be applied to the problem. [ Numerics, Presolve]
MAXSCALEFACTOR	This determines the maximum scaling factor that can be applied during scaling. [ Numerics, Presolve]
MIPDUALREDUCTIONS	Branch and Bound: Limits operations that can reduce the MIP solution space. [ Presolve]
MIPPRESOLVE	Branch and Bound: Type of integer processing to be performed. [ Bit-vector, Branch and Bound Search, Presolve]
NODEPROBINGEFFORT	Adjusts the overall level of node probing. [ Branch and Bound Search, Presolve]
PENALTY	Minimum absolute penalty variable coefficient. [ Presolve]
PREANALYTICCENTER	Determines if analytic centers should be computed and used for variable fixing and the generation of alternative reduced costs (-1: Auto 0: Off, 1: Fixing, 2: Redcost, 3: Both) [ Barrier, Presolve]
PREBASISRED	Determines if a lattice basis reduction algorithm should be attempted as part of presolve [ Presolve]
PREBNDREDCONE	Determines if second order cone constraints should be used for inferring bound reductions on variables when solving a MIP. [ Presolve]
PREBNDREDQUAD	Determines if convex quadratic constraints should be used for inferring bound reductions on variables when solving a MIP. [ Presolve, Quadratic]
PRECLIQUESTRATEGY	Determines how much effort to spend on clique covers in presolve. [ Presolve]
PRECOEFELIM	Presolve: Specifies whether the optimizer should attempt to recombine constraints in order to reduce the number of non zero coefficients when presolving a mixed integer problem. [ Presolve]
PRECOMPONENTS	Presolve: determines whether small independent components should be detected and solved as individual subproblems during root node processing. [ Presolve]
PRECOMPONENTSEFFORT	Presolve: adjusts the overall effort for the independent component presolver. [ Presolve]
PRECONEDECOMP	Presolve: decompose regular and rotated cones with more than two elements and apply Outer Approximation on the resulting components. [ Presolve, Quadratic]
PRECONFIGURATION	MIP Presolve: determines whether binary rows with only few repeating coefficients should be reformulated. [ Presolve]
PRECONVERTOBJTOCONS	Presolve: convert a linear or quadratic objective function into an objective transfer constraint [ Presolve, Problem Transformation]
PRECONVERTSEPARABLE	Presolve: reformulate problems with a non-diagonal quadratic objective and/or constraints as diagonal quadratic or second-order conic constraints. [ Presolve, Problem Transformation]
PREDOMCOL	Presolve: Determines the level of dominated column removal reductions to perform when presolving a mixed integer problem. [ Presolve]
PREDOMROW	Presolve: Determines the level of dominated row removal reductions to perform when presolving a problem. [ Presolve]
PREDUPROW	Presolve: Determines the type of duplicate rows to look for and eliminate when presolving a problem. [ Presolve]
PREELIMQUAD	Presolve: Allows for elimination of quadratic variables via doubleton rows. [ Presolve, Quadratic]
PREFOLDING	Presolve: Determines if a folding procedure should be used to aggregate continuous columns in an equitable partition. [ Presolve]
PREIMPLICATIONS	Presolve: Determines whether to use implication structures to remove redundant rows. [ Presolve]
PRELINDEP	Presolve: Determines whether to check for and remove linearly dependent equality constraints when presolving a problem. [ Presolve]
PREOBJCUTDETECT	Presolve: Determines whether to check for constraints that are parallel or near parallel to a linear objective function, and which can safely be removed. [ Presolve]
PREPERMUTE	This bit-vector control (see Section .) specifies whether to randomly permute rows, columns and MIP entities when starting the presolve. With the default value 0, no permutation will take place. [ Bit-vector, Presolve, Problem Transformation]
PREPERMUTESEED	This control sets the seed for the pseudo-random number generator for permuting the problem when starting the presolve. [ Presolve, Problem Transformation]
PREPROBING	Presolve: Amount of probing to perform on binary variables during presolve. [ Presolve]
PREPROTECTDUAL	Presolve: specifies whether the presolver should protect a given dual solution by maintaining the same level of dual feasibility. [ LP, Presolve]
PRESOLVE	This control determines whether presolving should be performed prior to starting the main algorithm. [ Presolve]
PRESOLVEMAXGROW	Limit on how much the number of non-zero coefficients is allowed to grow during presolve, specified as a ratio of the number of non-zero coefficients in the original problem. [ Limits, Presolve]
PRESOLVEOPS	This bit-vector control (see Section .) specifies the operations which are performed during the presolve. [ Bit-vector, Presolve]
PRESOLVEPASSES	Number of reduction rounds to be performed in presolve [ Limits, Presolve]
PRESORT	This bit-vector control (see Section .) specifies whether to sort rows, columns and MIP entities by their names when starting the presolve. With the default value 0, no sorting will take place. [ Bit-vector, Presolve, Problem Transformation]
PWLDUALREDUCTIONS	This parameter specifies whether dual reductions should be applied to reduce the number of columns, rows and SOS-constraints added when transforming piecewise linear objectives and constraints to MIP structs. [ Piecewise Linear and General Constraints, Presolve, Problem Transformation]
PWLNONCONVEXTRANSFORMATION	This control specifies the reformulation method for piecewise linear constraints at the beginning of the search. [ Piecewise Linear and General Constraints, Presolve, Problem Transformation]
SYMMETRY	Adjusts the overall amount of effort for symmetry detection. [ Presolve]
SYMSELECT	Adjusts the overall amount of effort for symmetry detection. [ Presolve]
TRACE	Display the infeasibility diagnosis during presolve. [ Logging, Presolve]

Presolve attributes

PRESOLVEINDEX	Presolve: The row or column index on which presolve detected a problem to be infeasible or unbounded. [ Presolve]
PRESOLVESTATE	Problem status as a bit-vector (compare Section .). [ Bit-vector, Presolve]

Primal Dual Hybrid Gradient

Reference section for functions, controls, and attributes related to the Primal Dual Hybrid Gradient solver, an iterative solver for very large LP relaxations.

Primal Dual Hybrid Gradient controls

BARALG	This control determines which barrier algorithm is used to solve the problem. [ Barrier, LP, Primal Dual Hybrid Gradient]
BARCORES	If set to a positive integer it determines the number of physical CPU cores assumed to be present in the system by the barrier and hybrid gradient algorithms. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
BARCRASH	Newton barrier and hybrid gradient: This determines the type of crash used for the crossover. [ Barrier, Primal Dual Hybrid Gradient]
BARDUALSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, representing the tolerance for dual infeasibilities. [ Barrier, Primal Dual Hybrid Gradient, Tolerances]
BARGAPSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, representing the tolerance for the relative duality gap. [ Barrier, Primal Dual Hybrid Gradient]
BARHGEXTRAPOLATE	Extrapolation parameter for the hybrid gradient algorithm. [ Primal Dual Hybrid Gradient]
BARHGMAXRESTARTS	The maximum number of restarts in the hybrid gradient algorithm. [ Primal Dual Hybrid Gradient]
BARHGOPS	Bit-vector control (see Section .) options for the hybrid gradient algorithm. Bits 1, 2 and 3 control which norms of the coefficient matrix are used for solution normalization. The normalization factor is the maximum of the selected norms. By default, or if all three bits are set to 0, the infinity norm is used. The omega parameter referenced in bits 4, 5 and 6 is a measure of the relative magnitudes of the objective and the right-hand side. [ Bit-vector, Primal Dual Hybrid Gradient]
BAROUTPUT	Newton barrier and hybrid gradient: This specifies the level of solution output provided. [ Barrier, Logging, Primal Dual Hybrid Gradient]
BARPRIMALSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, indicating the tolerance for primal infeasibilities. [ Barrier, Primal Dual Hybrid Gradient, Tolerances]
BARSTART	Controls the computation of the starting point and warm-starting for the Newton barrier and the hybrid gradient algorithms. [ Barrier, Primal Dual Hybrid Gradient]
BARTHREADS	If set to a positive integer it determines the number of threads implemented to run the Newton-barrier and hybrid gradient algorithms. [ Barrier, Parallel, Primal Dual Hybrid Gradient]
CROSSOVER	Newton barrier and hybrid gradient: This control determines whether the barrier method will cross over to the simplex method when at optimal solution has been found, to provide an end basis (see XPRSgetbasis, XPRSwritebasis) and advanced sensitivity analysis information (see XPRSobjsa, XPRSrhssa, XPRSbndsa). [ Barrier, Primal Dual Hybrid Gradient]
CROSSOVERACCURACYTOL	Newton barrier: This control determines how crossover adjusts the default relative pivot tolerance. [ Barrier, Primal Dual Hybrid Gradient]
CROSSOVERITERLIMIT	Newton barrier and hybrid gradient: The maximum number of iterations that will be performed in the crossover procedure before the optimization process terminates. [ Barrier, Primal Dual Hybrid Gradient]
CROSSOVEROPS	Newton barrier and hybrid gradient: a bit-vector (see Section .) for adjusting the behavior of the crossover procedure. [ Barrier, Bit-vector, Primal Dual Hybrid Gradient]
CROSSOVERTHREADS	Determines the maximum number of threads that parallel crossover is allowed to use. [ Barrier, Parallel, Primal Dual Hybrid Gradient]

Problem Creation

Reference section for functions, controls, and attributes related to problem creation.

Problem Creation library functions

XPRSaddcols, XPRSaddcols64	Adds columns to the optimizer matrix. [ Problem Creation]
XPRSaddgencons, XPRSaddgencons64	Adds one or more general constraints to the problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSaddnames	When a model is loaded, the rows, columns, sets, piecewise linear and general constraints of the model may not have names associated with them. [ Problem Creation]
XPRSaddobj	Appends an objective function with the given coefficients to a multi-objective problem. [ Multiobjective, Problem Creation]
XPRSaddpwlcons, XPRSaddpwlcons64	Adds one or more piecewise linear constraints to the problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSaddqmatrix, XPRSaddqmatrix64	Adds a new quadratic matrix into a row defined by triplets. [ Problem Creation, Quadratic]
XPRSaddrows, XPRSaddrows64	Adds rows to the optimizer matrix. [ Problem Creation]
XPRSaddsets, XPRSaddsets64	Allows sets to be added to the problem after passing it to the Optimizer using the input routines. [ MIP Entities, Problem Creation]
XPRScopyprob	Copies information defined for one problem to another. [ Problem Creation]
XPRScreateprob	Sets up a new problem within the Optimizer. [ Problem Creation]
XPRSdelcols	Delete columns from a matrix. [ Problem Creation]
XPRSdelgencons	Delete general constraints from a problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSdelindicators	Delete indicator constraints. [ MIP Entities, Problem Creation]
XPRSdelobj	Removes an objective function from a multi-objective problem. [ Problem Creation]
XPRSdelpwlcons	Delete piecewise linear constraints from a problem. [ Piecewise Linear and General Constraints, Problem Creation]
XPRSdelqmatrix	Deletes the quadratic part of a row or of the objective function. [ Problem Creation, Quadratic]
XPRSdelrows	Delete rows from a matrix. [ Problem Creation]
XPRSdelsets	Delete sets from a problem. [ MIP Entities, Problem Creation]
XPRSdestroyprob	Removes a given problem and frees any memory associated with it following manipulation and optimization. [ Problem Creation]
XPRSreadprob	Reads an (X)MPS or LP format matrix from file. [ File IO, Problem Creation]
XPRSsetindicators	Specifies that a set of rows in the matrix will be treated as indicator constraints during a tree search. [ Problem Creation]

Problem Creation controls

CHECKINPUTDATA	Check input arrays for bad data. [ File IO, Problem Creation]
EXTRACOLS	The initial number of extra columns to allow for in the matrix. [ Problem Creation]
EXTRAELEMS	The initial number of extra matrix elements to allow for in the matrix, including coefficients for cuts. [ Problem Creation]
EXTRAMIPENTS	The initial number of extra MIP entities to allow for. [ Problem Creation]
EXTRAROWS	The initial number of extra rows to allow for in the matrix, including cuts. [ Problem Creation]
EXTRASETELEMS	The initial number of extra elements in sets to allow for in the matrix. [ Problem Creation]
EXTRASETS	The initial number of extra sets to allow for in the matrix. [ Problem Creation]
INPUTTOL	The tolerance on input values elements. [ File IO, Problem Creation, Tolerances]
KEEPNROWS	How nonbinding rows should be handled by the MPS reader. [ File IO, Problem Creation]
MAXMCOEFFBUFFERELEMS	The maximum number of matrix coefficients to buffer before flushing into the internal representation of the problem. [ Problem Creation]

Problem Information

Reference section for functions, controls, and attributes related to querying information about a problem from the Optimizer.

Problem Information library functions

XPRSgetcoef	Returns a single coefficient in the constraint matrix. [ Problem Information]
XPRSgetcols, XPRSgetcols64	Returns the nonzeros in the constraint matrix for the columns in a given range. [ Problem Information]
XPRSgetcoltype	Returns the column types for the columns in a given range. [ MIP Entities, Problem Information]
XPRSgetdirs	Used to return the directives that have been loaded into a matrix. [ Branching, Problem Information]
XPRSgetgencons, XPRSgetgencons64	Returns the general constraints y = f(x1, ..., xn, c1, ..., cm) in a given range. [ Piecewise Linear and General Constraints, Problem Information]
XPRSgetindex	Returns the index for a specified row or column name. [ Problem Information]
XPRSgetindicators	Returns the indicator constraint condition (indicator variable and complement flag) associated to the rows in a given range. [ Problem Information]
XPRSgetlb	Returns the lower bounds for the columns in a given range. [ Problem Information]
XPRSgetmipentities, XPRSgetmipentities64	Retrieves integr and entity information about a problem. [ MIP Entities, Problem Information]
XPRSgetmqobj, XPRSgetmqobj64	Returns the nonzeros in the quadratic objective coefficients matrix for the columns in a given range. [ Problem Information, Quadratic]
XPRSgetobj	Returns the objective function coefficients for the columns in a given range. [ Problem Information]
XPRSgetobjn	For a given objective function, returns the objective coefficients for the columns in a given range. [ Multiobjective, Problem Information]
XPRSgetpresolvemap	Returns the mapping of the row and column numbers from the presolve problem back to the original problem. [ Presolve, Problem Information]
XPRSgetprobname	Returns the current problem name. [ Problem Information]
XPRSgetpwlcons, XPRSgetpwlcons64	Returns the piecewise linear constraints y = f(x) in a given range. [ Piecewise Linear and General Constraints, Problem Information]
XPRSgetqobj	Returns a single quadratic objective function coefficient corresponding to the variable pair (objqcol1, objqcol2) of the Hessian matrix. [ Problem Information, Quadratic]
XPRSgetqrowcoeff	Returns a single quadratic constraint coefficient corresponding to the variable pair (rowqcol1, rowqcol2) of the Hessian of a given constraint. [ Problem Information, Quadratic]
XPRSgetqrowqmatrix	Returns the nonzeros in a quadratic constraint coefficients matrix for the columns in a given range. [ Problem Information, Quadratic]
XPRSgetqrowqmatrixtriplets	Returns the nonzeros in a quadratic constraint coefficients matrix as triplets (index pairs with coefficients). [ Problem Information, Quadratic]
XPRSgetqrows	Returns the list indices of the rows that have quadratic coefficients. [ Problem Information, Quadratic]
XPRSgetrhs	Returns the right hand side elements for the rows in a given range. [ Problem Information]
XPRSgetrhsrange	Returns the right hand side range values for the rows in a given range. [ Problem Information]
XPRSgetrowflags	Retrieve if a range of rows have been set up as special rows. [ Problem Information]
XPRSgetrows, XPRSgetrows64	Returns the nonzeros in the constraint matrix for the rows in a given range. [ Problem Information]
XPRSgetrowtype	Returns the row types for the rows in a given range. [ Problem Information]
XPRSgetub	Returns the upper bounds for the columns in a given range. [ Problem Information]
XPRSsetprobname	Sets the current default problem name. [ Problem Information]

Problem Information attributes

COLS	Number of columns (i.e. variables) in the matrix. [ Problem Information]
CONEELEMS	Number of second order cone coefficients in the problem. [ Problem Information, Quadratic]
CONES	Number of second order and rotated second order cones in the problem. [ Problem Information, Quadratic]
ELEMS	Number of matrix nonzeros (elements). [ Problem Information]
GENCONCOLS	Number of input variables in general constraints (i.e. MIN/MAX/AND/OR/ABS constraints) in the problem. [ Piecewise Linear and General Constraints, Problem Information]
GENCONS	The number of general constraints (i.e. MIN/MAX/AND/OR/ABS constraints) in the problem. [ Piecewise Linear and General Constraints, Problem Information]
GENCONVALS	Number of constant values in general constraints (MIN/MAX constraints) in the problem. [ Piecewise Linear and General Constraints, Problem Information]
INDICATORS	Number of indicator constrains in the problem. [ MIP Entities, Problem Information]
INPUTCOLS	Number of columns (i.e. variables) in the original matrix before nonlinear reformulations. [ Problem Information]
INPUTROWS	Number of rows (i.e. constraints) in the original matrix before nonlinear reformulations. [ Problem Information]
MATRIXNAME	The matrix name. [ Problem Information]
MIPENTS	Number of MIP entities (i.e. binary, integer, semi-continuous, partial integer, and semi-continuous integer variables) but excluding the number of special ordered sets. [ MIP Entities, Problem Information]
OBJRHS	Fixed part of the objective function. [ Problem Information]
OBJSENSE	Sense of the optimization being performed. [ Problem Information]
OBJVAL	Value of the objective function of the last problem solved with XPRSoptimize. [ Problem Information, Solution Process]
ORIGINALCOLS	Number of columns (i.e. variables) in the original matrix before presolving. [ Problem Information]
ORIGINALGENCONCOLS	Number of input variables in general constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALGENCONS	Number of general constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALGENCONVALS	Number of constant values in general constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALINDICATORS	Number of indicator constraints in the original matrix before presolving. [ MIP Entities, Problem Information]
ORIGINALMIPENTS	Number of MIP entities (i.e. binary, integer, semi-continuous, partial integer, and semi-continuous integer variables) but excluding the number of special ordered sets in the original matrix before presolving. [ MIP Entities, Problem Information]
ORIGINALPWLPOINTS	Number of breakpoints of piecewise linear constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALPWLS	Number of piecewise linear constraints in the original problem before presolving. [ Piecewise Linear and General Constraints, Problem Information]
ORIGINALQCELEMS	Number of quadratic row coefficients in the original matrix before presolving. [ Problem Information, Quadratic]
ORIGINALQCONSTRAINTS	Number of rows with quadratic coefficients in the original matrix before presolving. [ Problem Information, Quadratic]
ORIGINALQELEMS	Number of quadratic non-zeros in the original objective before presolving. [ Problem Information, Quadratic]
ORIGINALROWS	Number of rows (i.e. constraints) in the original matrix before presolving. [ Problem Information]
ORIGINALSETMEMBERS	Number of variables within special ordered sets (set members) in the original matrix before presolving. [ MIP Entities, Problem Information]
ORIGINALSETS	Number of special ordered sets in the original matrix before presolving. [ MIP Entities, Problem Information]
PWLCONS	Number of piecewise linear constraints in the problem. [ Piecewise Linear and General Constraints, Problem Information]
PWLPOINTS	Number of breakpoints of piecewise linear constraints in the problem. [ Piecewise Linear and General Constraints, Problem Information]
QCELEMS	Number of quadratic row coefficients in the matrix. [ Problem Information, Quadratic]
QCONSTRAINTS	Number of rows with quadratic coefficients in the matrix. [ Problem Information, Quadratic]
QELEMS	Number of quadratic non-zeros in the objective. [ Problem Information, Quadratic]
ROWS	Number of rows (i.e. constraints) in the matrix. [ Problem Information]
SETMEMBERS	Number of variables within special ordered sets (set members) in the matrix. [ MIP Entities, Problem Information]
SETS	Number of special ordered sets in the matrix. [ MIP Entities, Problem Information]
SPARECOLS	Number of spare columns in the matrix. [ Problem Information]
SPAREELEMS	Number of spare matrix elements in the matrix. [ Problem Information]
SPAREMIPENTS	Number of spare MIP entities in the matrix. [ MIP Entities, Problem Information]
SPAREROWS	Number of spare rows in the matrix. [ Problem Information]
SPARESETELEMS	Number of spare set elements in the matrix. [ MIP Entities, Problem Information]
SPARESETS	Number of spare sets in the matrix. [ MIP Entities, Problem Information]

Problem Input

Reference section for functions, controls, and attributes related to problem input. The load functions in this section can be used to load an entire optimization problem into the Optimizer, which can be considerably faster than incrementally creating a problem.

Problem Input library functions

XPRSloaddelayedrows	Specifies that a set of rows in the matrix will be treated as delayed rows during a tree search. [ Cuts, Problem Input]
XPRSloadlp, XPRSloadlp64	Enables the user to pass a matrix directly to the Optimizer, rather than reading the matrix from a file. [ LP, Problem Input]
XPRSloadmip, XPRSloadmip64	Used to load a MIP problem into the Optimizer data structures. [ MIP Entities, Problem Input]
XPRSloadmiqcqp, XPRSloadmiqcqp64	Used to load a mixed integer quadratic problem with quadratic constraints into the Optimizer data structure. [ Problem Input, Quadratic]
XPRSloadmiqp, XPRSloadmiqp64	Used to load a MIQP problem, hence a MIP with quadratic objective coefficients, into the Optimizer data structures. [ Problem Input, Quadratic]
XPRSloadqcqp, XPRSloadqcqp64	Used to load a quadratic problem with quadratic side constraints into the Optimizer data structure. [ Problem Input, Quadratic]
XPRSloadqp, XPRSloadqp64	Used to load a quadratic problem into the Optimizer data structure. [ Problem Input, Quadratic]

Problem Modification

Reference section for functions, controls, and attributes related to Problem Modification. Make adjustments to the current problem in the Optimizer.

Problem Modification library functions

XPRSchgbounds	Used to change the bounds on columns in the matrix. [ Problem Modification]
XPRSchgcoef	Used to change a single coefficient in the matrix. [ Problem Modification]
XPRSchgcoltype	Used to change the type of a specified set of columns in the matrix. [ MIP Entities, Problem Modification]
XPRSchgglblimit	Used to change semi-continuous or semi-integer lower bounds, or upper limits on partial integers. [ MIP Entities, Problem Modification]
XPRSchgmcoef, XPRSchgmcoef64	Used to change multiple coefficients in the matrix. [ Problem Modification]
XPRSchgmqobj, XPRSchgmqobj64	Used to change multiple quadratic coefficients in the objective function. [ Problem Modification, Quadratic]
XPRSchgobj	Used to change the objective function coefficients. [ Problem Modification]
XPRSchgobjn	Modifies one or more coefficients of an objective function in a multi-objective problem. [ Multiobjective, Problem Modification]
XPRSchgobjsense	Changes the problem's objective function sense to minimize or maximize. [ Problem Modification]
XPRSchgqobj	Used to change a single quadratic coefficient in the objective function corresponding to the variable pair (objqcol1,objqcol2) of the Hessian matrix. [ Problem Modification, Quadratic]
XPRSchgqrowcoeff	Changes a single quadratic coefficient in a row. [ Problem Modification, Quadratic]
XPRSchgrhs	Used to change righthand side values of the problem. [ Problem Modification]
XPRSchgrhsrange	Used to change the range for a row of the problem matrix. [ Problem Modification]
XPRSchgrowtype	Used to change the type of a row in the matrix. [ Problem Modification]
XPRSclearrowflags	Clears extra information attached to a range of rows. [ Problem Modification]
XPRSfixmipentities	Fixes all the MIP entities to the values of the last found MIP solution. [ MIP Entities, Problem Modification]

Problem Transformation

Reference section for functions, controls, and attributes related to transformation for specific types of constraints before the actual solution process begins and problem permutation.

Problem Transformation controls

AUTOSCALING	Whether the Optimizer should automatically select between different scaling algorithms. [ Numerics, Problem Transformation]
DUALIZE	For a linear problem or the initial linear relaxation of a MIP, determines whether to form and solve the dual problem. [ LP, Problem Transformation]
INDLINBIGM	During presolve, indicator constraints will be linearized using a BigM coefficient whenever that BigM coefficient is small enough. [ Presolve, Problem Transformation]
INDPRELINBIGM	During presolve, indicator constraints will be linearized using a BigM coefficient whenever that BigM coefficient is small enough. [ Presolve, Problem Transformation]
PRECONVERTOBJTOCONS	Presolve: convert a linear or quadratic objective function into an objective transfer constraint [ Presolve, Problem Transformation]
PRECONVERTSEPARABLE	Presolve: reformulate problems with a non-diagonal quadratic objective and/or constraints as diagonal quadratic or second-order conic constraints. [ Presolve, Problem Transformation]
PREPERMUTE	This bit-vector control (see Section .) specifies whether to randomly permute rows, columns and MIP entities when starting the presolve. With the default value 0, no permutation will take place. [ Bit-vector, Presolve, Problem Transformation]
PREPERMUTESEED	This control sets the seed for the pseudo-random number generator for permuting the problem when starting the presolve. [ Presolve, Problem Transformation]
PRESORT	This bit-vector control (see Section .) specifies whether to sort rows, columns and MIP entities by their names when starting the presolve. With the default value 0, no sorting will take place. [ Bit-vector, Presolve, Problem Transformation]
PWLDUALREDUCTIONS	This parameter specifies whether dual reductions should be applied to reduce the number of columns, rows and SOS-constraints added when transforming piecewise linear objectives and constraints to MIP structs. [ Piecewise Linear and General Constraints, Presolve, Problem Transformation]
PWLNONCONVEXTRANSFORMATION	This control specifies the reformulation method for piecewise linear constraints at the beginning of the search. [ Piecewise Linear and General Constraints, Presolve, Problem Transformation]
SCALING	This bit-vector control (see Section .) determines how the Optimizer will rescale a model internally before optimization. If set to 0, no scaling will take place. [ Bit-vector, Numerics, Problem Transformation]
TUNERPERMUTE	Tuner: Defines the number of permutations to solve for each control setting. [ Problem Transformation, Tuner]

Propagation

Reference section for functions, controls, and attributes related to Propagation, which denotes local logical deductions on column bounds during the Branch and Bound Search. Propagation routines are more lightweight than presolving and are hence applicable at every node of the search tree.

Propagation controls

ALTERNATIVEREDCOSTS	Controls aggressiveness of searching for alternative reduced cost [ Propagation]
GLOBALSPATIALBRANCHPROPAGATIONEFFORT	Limits the effort that is spent on propagation during spatial branching. [ Global, Propagation]

Quadratic

Reference section for functions, controls, and attributes related to optimization problems with Quadratic terms in the objective function (called 'QP' or 'MIQP'), or in the rows of the problem (called 'QCP' or 'MIQCP'), or both in the objective and the rows.

Quadratic library functions

XPRSaddqmatrix, XPRSaddqmatrix64	Adds a new quadratic matrix into a row defined by triplets. [ Problem Creation, Quadratic]
XPRSchgmqobj, XPRSchgmqobj64	Used to change multiple quadratic coefficients in the objective function. [ Problem Modification, Quadratic]
XPRSchgqobj	Used to change a single quadratic coefficient in the objective function corresponding to the variable pair (objqcol1,objqcol2) of the Hessian matrix. [ Problem Modification, Quadratic]
XPRSchgqrowcoeff	Changes a single quadratic coefficient in a row. [ Problem Modification, Quadratic]
XPRSdelqmatrix	Deletes the quadratic part of a row or of the objective function. [ Problem Creation, Quadratic]
XPRSgetmqobj, XPRSgetmqobj64	Returns the nonzeros in the quadratic objective coefficients matrix for the columns in a given range. [ Problem Information, Quadratic]
XPRSgetqobj	Returns a single quadratic objective function coefficient corresponding to the variable pair (objqcol1, objqcol2) of the Hessian matrix. [ Problem Information, Quadratic]
XPRSgetqrowcoeff	Returns a single quadratic constraint coefficient corresponding to the variable pair (rowqcol1, rowqcol2) of the Hessian of a given constraint. [ Problem Information, Quadratic]
XPRSgetqrowqmatrix	Returns the nonzeros in a quadratic constraint coefficients matrix for the columns in a given range. [ Problem Information, Quadratic]
XPRSgetqrowqmatrixtriplets	Returns the nonzeros in a quadratic constraint coefficients matrix as triplets (index pairs with coefficients). [ Problem Information, Quadratic]
XPRSgetqrows	Returns the list indices of the rows that have quadratic coefficients. [ Problem Information, Quadratic]
XPRSloadmiqcqp, XPRSloadmiqcqp64	Used to load a mixed integer quadratic problem with quadratic constraints into the Optimizer data structure. [ Problem Input, Quadratic]
XPRSloadmiqp, XPRSloadmiqp64	Used to load a MIQP problem, hence a MIP with quadratic objective coefficients, into the Optimizer data structures. [ Problem Input, Quadratic]
XPRSloadqcqp, XPRSloadqcqp64	Used to load a quadratic problem with quadratic side constraints into the Optimizer data structure. [ Problem Input, Quadratic]
XPRSloadqp, XPRSloadqp64	Used to load a quadratic problem into the Optimizer data structure. [ Problem Input, Quadratic]

Quadratic console functions

CHECKCONVEXITY

Convexity checker.
[ Linear Algebra, Quadratic]

Quadratic controls

EIGENVALUETOL	A quadratic matrix is considered not to be positive semi-definite, if its smallest eigenvalue is smaller than the negative of this value. [ Quadratic, Tolerances]
IFCHECKCONVEXITY	Determines if the convexity of the problem is checked before optimization. [ Presolve, Quadratic]
MIQCPALG	This control determines which algorithm is to be used to solve mixed integer quadratic constrained and mixed integer second order cone problems. [ Branch and Bound Search, Quadratic]
PREBNDREDQUAD	Determines if convex quadratic constraints should be used for inferring bound reductions on variables when solving a MIP. [ Presolve, Quadratic]
PRECONEDECOMP	Presolve: decompose regular and rotated cones with more than two elements and apply Outer Approximation on the resulting components. [ Presolve, Quadratic]
PREELIMQUAD	Presolve: Allows for elimination of quadratic variables via doubleton rows. [ Presolve, Quadratic]
QCCUTS	Branch and Bound: Limit on the number of rounds of outer approximation cuts generated for the root node, when solving a mixed integer quadratic constrained or mixed integer second order conic problem with outer approximation. [ Cuts, Quadratic]
QCROOTALG	This control determines which algorithm is to be used to solve the root of a mixed integer quadratic constrained or mixed integer second order cone problem, when outer approximation is used. [ Quadratic, Root]
QSIMPLEXOPS	Controls the behavior of the quadratic simplex solvers via a bit-vector (see Section .). [ Bit-vector, Quadratic, Simplex]
QUADRATICUNSHIFT	Determines whether an extra solution purification step is called after a solution found by the quadratic simplex (either primal or dual). [ Quadratic, Simplex]
REPAIRINDEFINITEQ	Controls if the optimizer should make indefinite quadratic matrices positive definite when it is possible. [ Quadratic]
RLTCUTS	Determines whether RLT cuts should be separated in the Xpress Global Solver. [ Cuts, Quadratic]
TREEQCCUTS	Branch and Bound: Limit on the number of rounds of outer approximation cuts generated for nodes other than the root node, when solving a mixed integer quadratic constrained or mixed integer second order conic problem with outer approximation. [ Branch and Bound Search, Quadratic]

Quadratic attributes

CONEELEMS	Number of second order cone coefficients in the problem. [ Problem Information, Quadratic]
CONES	Number of second order and rotated second order cones in the problem. [ Problem Information, Quadratic]
ORIGINALQCELEMS	Number of quadratic row coefficients in the original matrix before presolving. [ Problem Information, Quadratic]
ORIGINALQCONSTRAINTS	Number of rows with quadratic coefficients in the original matrix before presolving. [ Problem Information, Quadratic]
ORIGINALQELEMS	Number of quadratic non-zeros in the original objective before presolving. [ Problem Information, Quadratic]
QCELEMS	Number of quadratic row coefficients in the matrix. [ Problem Information, Quadratic]
QCONSTRAINTS	Number of rows with quadratic coefficients in the matrix. [ Problem Information, Quadratic]
QELEMS	Number of quadratic non-zeros in the objective. [ Problem Information, Quadratic]

Root

Reference section for functions, controls, and attributes related to the root node of the Branch and Bound Search. During root node processing, all derived information such as cutting planes or domain reductions are still valid for the whole problem before the search enters the tree search. For this reason, the root node deserves special attention. The optimizer will typically spend a larger amount of time at the root node than at any other node deeper in the tree.

Root controls

BACKGROUNDMAXTHREADS	Limit the number of threads to use in background jobs (for example in parallel to the root cut loop). [ Parallel, Root]
BACKGROUNDSELECT	Bit-vector control (see Section .) to select which tasks to run in background jobs (for example in parallel to the root cut loop). [ Bit-vector, Heuristics, Root]
COVERCUTS	Branch and Bound: The number of rounds of lifted cover inequalities at the root node. [ Cuts, Root]
CUTSELECT	A bit-vector (see Section .) providing detailed control of the cuts created for the root node of a MIP solve. Use TREECUTSELECT to control cuts during the tree search. [ Bit-vector, Cuts, Root]
GOMCUTS	Branch and Bound: The number of rounds of Gomory or lift-and-project cuts at the root node. [ Cuts, Root]
HEURSEARCHBACKGROUNDSELECT	Bit-vector control (see Section .) to select which large neighborhood searches to run in the background (for example in parallel to the root cut loop). [ Bit-vector, Heuristics, Root]
HEURSEARCHROOTCUTFREQ	How frequently to run the local search heuristic during root cutting. [ Heuristics, Root]
HEURSEARCHROOTSELECT	A bit-vector control (see Section .) for selecting which local search heuristics to apply on the root node of a MIP solve. Use HEURSEARCHTREESELECT to control local search heuristics during the tree search. [ Bit-vector, Heuristics, Root]
LNPBEST	Number of infeasible MIP entities to create lift-and-project cuts for during each round of Gomory cuts at the root node (see GOMCUTS). [ Cuts, Root]
LPFLAGS	A bit-vector control (see Section .) which defines the algorithm for solving an LP problem or the initial LP relaxation of a MIP problem. [ Bit-vector, LP, Root]
MIPFRACREDUCE	Branch and Bound: Specifies how often the optimizer should run a heuristic to reduce the number of fractional integer variables in the node LP solutions. [ Branch and Bound Search, Root]
QCROOTALG	This control determines which algorithm is to be used to solve the root of a mixed integer quadratic constrained or mixed integer second order cone problem, when outer approximation is used. [ Quadratic, Root]
ROOTPRESOLVE	Determines if presolving should be performed on the problem after the tree search has finished with root cutting and heuristics. [ Root]

Save Restore

Reference section for functions, controls, and attributes related to Save and Restore functionality of the Optimizer.

Save Restore library functions

XPRSrestore	Restores the Optimizer's data structures from a file created by XPRSsave (SAVE). [ File IO, Save Restore]
XPRSsave, XPRSsaveas	Saves the current data structures to file and terminates the run [ File IO, Save Restore]

Sensitivity Analysis

Reference section for functions, controls, and attributes related to Sensitivity Analysis.

Sensitivity Analysis library functions

XPRSbndsa	Returns upper and lower sensitivity ranges for specified variables' lower and upper bounds. [ LP, Sensitivity Analysis]
XPRSestimaterowdualranges	Performs a dual side range sensitivity analysis, i.e. calculates estimates for the possible ranges for dual values. [ LP, Sensitivity Analysis]
XPRSobjsa	Returns upper and lower sensitivity ranges for specified objective function coefficients. [ LP, Sensitivity Analysis]
XPRSrhssa	Returns upper and lower sensitivity ranges for specified right hand side (RHS) function coefficients. [ LP, Sensitivity Analysis]

Simplex

Reference section for functions, controls, and attributes related to the Simplex algorithms (primal, dual, network) that the Optimizer uses to solve linear programming problems (LPs) as standalone optimization problems or as relaxations during the Branch and Bound Search.

Simplex library functions

XPRSgetpivotorder	Returns the pivot order of the basic variables. [ LP, Simplex]
XPRSgetpivots	Returns a list of potential leaving variables if a specified variable enters the basis. [ LP, Simplex]
XPRSgetpresolvebasis	Returns the current basis from memory into the user's data areas. [ LP, Simplex]
XPRSpivot	Performs a simplex pivot by bringing variable enter into the basis and removing leave. [ Linear Algebra, Simplex]
XPRSsparsebtran	Post-multiplies a (row) vector provided by the user by the inverse of the current matrix. [ Linear Algebra, Simplex]
XPRSsparseftran	Pre-multiplies a (column) vector provided by the user by the inverse of the current matrix. [ Linear Algebra, Simplex]

Simplex controls

ALGAFTERNETWORK	The algorithm to be used for the clean up step after the network simplex solver. [ LP, Simplex]
CRASH	Simplex: This determines the type of crash used when the algorithm begins. [ Bit-vector, LP, Simplex]
DUALGRADIENT	Simplex: This specifies the dual simplex pricing method. [ LP, Simplex]
DUALPERTURB	The factor by which the problem will be perturbed prior to optimization by dual simplex. [ LP, Simplex]
DUALSTRATEGY	This bit-vector control (see Section .) specifies the dual simplex strategy. [ Bit-vector, LP, Simplex]
ETATOL	Tolerance on eta elements. [ Simplex, Tolerances]
FEASTOLPERTURB	This tolerance determines how much a feasible primal basic solution is allowed to be perturbed when performing basis changes. [ Simplex, Tolerances]
FORCEPARALLELDUAL	Dual simplex: specifies whether the dual simplex solver should always use the parallel simplex algorithm. [ LP, Simplex]
INVERTFREQ	Simplex: The frequency with which the basis will be inverted. [ Simplex]
INVERTMIN	Simplex: The minimum number of iterations between full inversions of the basis matrix. [ Simplex]
KEEPBASIS	Simplex: This determines whether the basis should be kept when reoptimizing a problem. [ LP, Simplex]
MARKOWITZTOL	The Markowitz tolerance used for the factorization of the basis matrix. [ LP, Simplex]
NETSTALLLIMIT	Limit the number of degenerate pivots of the network simplex algorithm, before switching to either primal or dual simplex, depending on ALGAFTERNETWORK. [ Limits, Simplex]
PIVOTTOL	Simplex: The zero tolerance for matrix elements. [ Simplex, Tolerances]
PPFACTOR	The partial pricing candidate list sizing parameter. [ Simplex]
PRICINGALG	Simplex: This determines the primal simplex pricing method. [ LP, Simplex]
PRIMALOPS	Primal simplex: allows fine tuning the variable selection in the primal simplex solver. [ Bit-vector, LP, Simplex]
PRIMALPERTURB	The factor by which the problem will be perturbed prior to optimization by primal simplex. [ LP, Simplex]
PRIMALUNSHIFT	Determines whether primal is allowed to call dual to unshift. [ LP, Simplex]
QSIMPLEXOPS	Controls the behavior of the quadratic simplex solvers via a bit-vector (see Section .). [ Bit-vector, Quadratic, Simplex]
QUADRATICUNSHIFT	Determines whether an extra solution purification step is called after a solution found by the quadratic simplex (either primal or dual). [ Quadratic, Simplex]
REFACTOR	Indicates whether the optimization should restart using the current representation of the factorization in memory. [ Branch and Bound Search, Simplex]
RELPIVOTTOL	Simplex: At each iteration a pivot element is chosen within a given column of the matrix. [ Simplex, Tolerances]
SIFTING	Determines whether to enable sifting algorithm with the dual simplex method. [ LP, Simplex]
SIFTPASSES	Determines how quickly we allow to grow the worker problems during the sifting algorithm. [ LP, Simplex]
SIFTPRESOLVEOPS	Determines the presolve operations for solving the subproblems during the sifting algorithm. [ LP, Simplex]
SIFTSWITCH	Determines which algorithm to use for solving the subproblems during sifting. [ LP, Simplex]

Simplex attributes

SIMPLEXITER

Number of simplex iterations performed.
[ LP, Simplex]

Solution Process

Reference section for functions, controls, and attributes related to the invocation of a solution algorithm of the Optimizer, and the most fundamental status information after the Optimizer returns.

Solution Process library functions

XPRSinterrupt	Interrupts the Optimizer algorithms. [ Solution Process]
XPRSlpoptimize	This function begins a search for the optimal continuous (LP) solution. [ LP, Solution Process]
XPRSmipoptimize	This function begins a tree search for the optimal MIP solution. [ MIP Entities, Solution Process]
XPRSoptimize	This function begins a search for the optimal solution of the problem. [ Solution Process]
XPRSpostsolve	Postsolve the current matrix when it is in a presolved state. [ Presolve, Solution Process]

Solution Process attributes

OBJVAL	Value of the objective function of the last problem solved with XPRSoptimize. [ Problem Information, Solution Process]
OPTIMIZETYPEUSED	The type of solver used in the last call to XPRSoptimize, XPRSmipoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ Solution Process]
SOLSTATUS	Status of the solution of the last problem solved with XPRSoptimize. [ Solution, Solution Process]
SOLVESTATUS	Status of the solve of the last problem solved with XPRSoptimize. [ Solution Process]
STOPSTATUS	Status of the optimization process. [ Solution Process]
TIME	Time spent solving the problem as measured by the optimizer. [ Solution Process]
WORK	Amount of deterministic algorithmic "work" spent since the invocation of the search process. [ Determinism, Solution Process]

Solution Refinement

Reference section for functions, controls, and attributes related to Solution Refinement, an iterative procedure that helps reducing numerical artifacts in a solution.

Solution Refinement controls

FEASTOLTARGET	This specifies the target feasibility tolerance for the solution refiner. [ Solution Refinement, Tolerances]
LPREFINEITERLIMIT	This specifies the simplex iteration limit the solution refiner can spend in attempting to increase the accuracy of an LP solution. [ LP, Solution Refinement]
MIPREFINEITERLIMIT	This defines an effort limit expressed as simplex iterations for the MIP solution refiner. [ Limits, Solution Refinement]
MIPTOLTARGET	Target MIPTOL value used by the automatic MIP solution refiner as defined by REFINEOPS. [ Solution Refinement, Tolerances]
OPTIMALITYTOLTARGET	This specifies the target optimality tolerance for the solution refiner. [ Solution Refinement, Tolerances]
REFINEOPS	This specifies when the solution refiner should be executed to reduce solution infeasibilities. [ Bit-vector, Solution Refinement]

Solution

Reference section for functions, controls, and attributes related to the handling of optimal or intermediate solutions.

Solution library functions

XPRSaddcbintsol	Declares a user integer solution callback function, called every time an integer solution is found by heuristics or during the Branch and Bound search. [ Callback, Solution]
XPRSaddcbpreintsol	Declares a user integer solution callback function, called when an integer solution is found by heuristics or during the branch and bound search, but before it is accepted by the Optimizer. [ Callback, Solution]
XPRSaddcbusersolnotify	Declares a callback function to be called each time a solution added by XPRSaddmipsol has been processed. [ Callback, Solution]
XPRSaddmipsol	Adds a new feasible, infeasible or partial MIP solution for the problem to the Optimizer. [ Solution]
XPRScalcobjective	Calculates the objective value of a given solution. [ Solution]
XPRScalcobjn	Calculates the objective value of the given objective function in a multi-objective problem. [ Multiobjective, Solution]
XPRScalcreducedcosts	Calculates the reduced cost values for a given (row) dual solution. [ Linear Algebra, Solution]
XPRScalcslacks	Calculates the row slack values for a given solution. [ Solution]
XPRScalcsolinfo	Calculates the required property of a solution, like maximum infeasibility of a given primal and dual solution. [ Solution]
XPRSgetcallbackduals	Returns the dual values dual value for this constraint from the solution associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolveduals	Returns the dual values from the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolveredcosts	Returns the reduced costs from the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolveslacks	Returns the slack values from the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackpresolvesolution	Returns the solution to the presolved problem associated with the current callback. [ Callback, Solution]
XPRSgetcallbackredcosts	Returns the reduced costs reduced cost for this variable from the solution associated with the current callback. [ Callback, Solution]
XPRSgetcallbackslacks	Returns the slack values slack value for this constraint from the solution associated with the current callback. [ Callback, Solution]
XPRSgetcallbacksolution	Returns the primal values primal value for this variable from the solution associated with the current callback. [ Callback, Solution]
XPRSgetdualray	Retrieves a dual ray (dual unbounded direction) for the current problem, if the problem is found to be infeasible. [ LP, Solution]
XPRSgetduals	Returns the dual values dual value for this constraint from the incumbent solution during or after optimization of a continuous problem with XPRSoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ LP, Solution]
XPRSgetinfeas	Returns a list of infeasible primal and dual variables. [ LP, Solution]
XPRSgetlastbarsol	Used to obtain the last barrier solution values following optimization that used the barrier solver. [ Barrier, Solution]
XPRSgetlpsol	Used to obtain the LP solution values following optimization. [ LP, Solution]
XPRSgetpresolvesol	Returns the solution for the presolved problem from memory. [ Presolve, Solution]
XPRSgetprimalray	Retrieves a primal ray (primal unbounded direction) for the current problem, if the problem is found to be unbounded. [ LP, Solution]
XPRSgetslacks	Returns the slack values slack value for this constraint from the incumbent solution during or after optimization with XPRSoptimize, XPRSmipoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ LP, Solution]
XPRSgetsolution	Returns the primal value of this variable from the incumbent solution during or after optimization with XPRSoptimize, XPRSmipoptimize, XPRSlpoptimize or XPRSnlpoptimize. [ Solution]
XPRSgetunbvec	Returns the index vector which causes the primal simplex or dual simplex algorithm to determine that a matrix is primal or dual unbounded respectively. [ LP, Solution]
XPRSloadlpsol	Loads an LP solution for the problem into the Optimizer. [ Data Input, LP, Solution]
XPRSloadmipsol	Loads a starting MIP solution for the problem into the Optimizer. [ Data Input, MIP Entities, Solution]
XPRSpostsolvesol	Postsolves a primal solution formulated in the presolved space into the corresponding solution formulated in the original space. [ Presolve, Solution]
XPRSreadbinsol	Reads a solution from a binary solution file. [ File IO, Solution]
XPRSreadslxsol	Reads an ASCII solution file .slx created by the XPRSwriteslxsol function. [ File IO, Solution]
XPRSremovecbintsol	Removes an integer solution callback function previously added by XPRSaddcbintsol. [ Callback, Solution]
XPRSremovecbpreintsol	Removes a pre-integer solution callback function previously added by XPRSaddcbpreintsol. [ Callback, Solution]
XPRSremovecbusersolnotify	Removes a user solution notification callback previously added by XPRSaddcbusersolnotify. [ Callback, Solution]
XPRSwritebinsol	Writes the current MIP or LP solution to a binary solution file for later input into the Optimizer. [ File IO, Solution]
XPRSwriteprtsol	Writes the current solution to a fixed format ASCII file, problem_name .prt. [ File IO, Solution]
XPRSwriteslxsol	Creates an ASCII solution file (.slx) using a similar format to MPS files. These files can be read back into the Optimizer using the XPRSreadslxsol function. [ File IO, Solution]
XPRSwritesol	Writes the current solution to a CSV format ASCII file, problem_name.asc (and .hdr). [ File IO, Solution]

Solution console functions

PRINTSOL	Write the current solution to screen. [ Solution]
READBINSOL	Reads a solution from a binary solution file. [ File IO, Solution]
READSLXSOL	Reads an ASCII solution file .slx created by the XPRSwriteslxsol function. [ File IO, Solution]
WRITEBINSOL	Writes the current MIP or LP solution to a binary solution file for later input into the Optimizer. [ File IO, Solution]
WRITEPRTSOL	Writes the current solution to a fixed format ASCII file, problem_name .prt. [ File IO, Solution]
WRITESLXSOL	Creates an ASCII solution file (.slx) using a similar format to MPS files. These files can be read back into the Optimizer using the XPRSreadslxsol function. [ File IO, Solution]
WRITESOL	Writes the current solution to a CSV format ASCII file, problem_name.asc (and .hdr). [ File IO, Solution]

Solution controls

CLAMPING	This bit-vector control (see Section .) allows for the adjustment of returned solution values such that they are always within bounds. [ Bit-vector, Numerics, Solution]
MAXMIPSOL	Branch and Bound: This specifies a limit on the number of integer solutions to be found by the Optimizer. [ Limits, Solution]

Solution attributes

MIPOBJVAL	Objective function value of the last integer solution found. [ Branch and Bound Search, Solution]
MIPSOLNODE	Node at which the last integer feasible solution was found. [ Branch and Bound Search, Solution]
MIPSOLS	Number of integer solutions that have been found. [ Branch and Bound Search, Solution]
MIPSOLTIME	Time at which the last integer feasible solution was found. [ Branch and Bound Search, Solution]
SOLSTATUS	Status of the solution of the last problem solved with XPRSoptimize. [ Solution, Solution Process]

System

Reference section for functions, controls, and attributes related to Computer hardware and system specifications.

System controls

CORESPERCPU	Used to override the detected value of the number of cores on a CPU. [ System]
CPUPLATFORM	Newton Barrier: Selects the AMD, Intel x86 or ARM vectorization instruction set that Barrier should run optimized code for. [ System]
CPUTIME	How time should be measured when timings are reported in the log and when checking against time limits [ System]

System attributes

CORESDETECTED	Number of logical cores detected by the optimizer, which is the total number of threads the hardware can execute across all CPUs. [ System]
CORESPERCPUDETECTED	Number of logical cores per CPU unit detected by the optimizer, which is the number of threads each CPU can execute. [ System]
CPUSDETECTED	Number of CPU units detected by the optimizer. [ System]
PHYSICALCORESDETECTED	The total number of physical cores across all CPUs detected by the optimizer. [ System]
PHYSICALCORESPERCPUDETECTED	The number of physical cores per CPU detected by the optimizer. [ System]
SYSTEMMEMORY	The amount of non problem specific memory used by the solver. [ Memory, System]

Tolerances

Reference section for functions, controls, and attributes related to feasibility and optimality tolerances.

Tolerances controls

BARDUALSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, representing the tolerance for dual infeasibilities. [ Barrier, Primal Dual Hybrid Gradient, Tolerances]
BARPRIMALSTOP	Newton barrier and hybrid gradient: This is a convergence parameter, indicating the tolerance for primal infeasibilities. [ Barrier, Primal Dual Hybrid Gradient, Tolerances]
EIGENVALUETOL	A quadratic matrix is considered not to be positive semi-definite, if its smallest eigenvalue is smaller than the negative of this value. [ Quadratic, Tolerances]
ELIMTOL	The Markowitz tolerance for the elimination phase of the presolve. [ Presolve, Tolerances]
ETATOL	Tolerance on eta elements. [ Simplex, Tolerances]
FEASTOL	This tolerance determines when a solution is treated as feasible. [ Tolerances]
FEASTOLPERTURB	This tolerance determines how much a feasible primal basic solution is allowed to be perturbed when performing basis changes. [ Simplex, Tolerances]
FEASTOLTARGET	This specifies the target feasibility tolerance for the solution refiner. [ Solution Refinement, Tolerances]
INPUTTOL	The tolerance on input values elements. [ File IO, Problem Creation, Tolerances]
MATRIXTOL	The zero tolerance on matrix elements. [ Tolerances]
MIPTOL	Branch and Bound: This is the tolerance within which a decision variable's value is considered to be integral. [ Tolerances]
MIPTOLTARGET	Target MIPTOL value used by the automatic MIP solution refiner as defined by REFINEOPS. [ Solution Refinement, Tolerances]
OPTIMALITYTOL	Simplex: This is the zero tolerance for reduced costs. [ Tolerances]
OPTIMALITYTOLTARGET	This specifies the target optimality tolerance for the solution refiner. [ Solution Refinement, Tolerances]
OUTPUTTOL	Zero tolerance on print values. [ File IO, Tolerances]
PIVOTTOL	Simplex: The zero tolerance for matrix elements. [ Simplex, Tolerances]
RELPIVOTTOL	Simplex: At each iteration a pivot element is chosen within a given column of the matrix. [ Simplex, Tolerances]
SOSREFTOL	The minimum relative gap between the ordering values of elements in a special ordered set. [ Tolerances]

Tuner

Reference section for functions, controls, and attributes related to the algorithmic tuning of control values to customize the Optimizer.

Tuner library functions

XPRStune	This function begins a tuner session for the current problem. [ Tuner]
XPRStuneprobsetfile	This function begins a tuner session for a set of problems. [ Tuner]
XPRStunerreadmethod	This function loads a user defined tuner method from the given file. [ File IO, Tuner]
XPRStunerwritemethod	This function writes the current tuner method to a given file or prints it to the console. [ File IO, Tuner]

Tuner console functions

TUNE	Console Tuner command. [ Tuner]

Tuner controls

TUNERHISTORY	Tuner: Whether to reuse and append to previous tuner results of the same problem. [ Tuner]
TUNERMAXTIME	Tuner: The maximum time in seconds that the tuner will run before it terminates. [ Limits, Tuner]
TUNERMETHOD	Tuner: Selects a factory tuner method. [ Tuner]
TUNERMETHODFILE	Tuner: Defines a file from which the tuner can read user-defined tuner method. [ File IO, Tuner]
TUNERMODE	Tuner: Whether to always enable the tuner or disable it. [ Tuner]
TUNEROUTPUT	Tuner: Whether to output tuner results and logs to the file system. [ File IO, Tuner]
TUNEROUTPUTPATH	Tuner: Defines a root path to which the tuner writes the result file and logs. [ File IO, Tuner]
TUNERPERMUTE	Tuner: Defines the number of permutations to solve for each control setting. [ Problem Transformation, Tuner]
TUNERSESSIONNAME	Tuner: Defines a session name for the tuner. [ Tuner]
TUNERTARGET	Tuner: Defines the tuner target -- what should be evaluated when comparing two runs with different control settings. [ Tuner]
TUNERTHREADS	Tuner: the number of threads used by the tuner. [ Parallel, Tuner]
TUNERVERBOSE	Tuner: whether the tuner should prints detailed information for each run. [ Logging, Tuner]

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