Xpress Release Notes

New in Release 8.11

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Xpress Mosel 5.4.0

Fixed in Release 8.11

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Mosel 5.4.0

Fixed in Release 8.10.1

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Xpress Mosel 5.2.4

Runtime Library

New in Release 8.10

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Xpress Mosel 5.2.2

mmnl 2.2.0

Fixed in Release 8.10

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Xpress Mosel 5.2.2

Fixed in Release 8.9.4

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Xpress Mosel 5.2.3

Fixed in Release 8.9.3

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Xpress Mosel 5.2.1

Fixed in Release 8.9.2

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Xpress Mosel 5.2.1

New in Release 8.9.1

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New in Release 8.9

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Fixed in Release 8.8.4

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Xpress Optimizer 35.01.05

• XPRSalter will now change the neutral row of the objective as well if the name of the row rather then **OBJ is specified.
• XPRSalter will now read floating point numbers in full accuracy.
• Improved numerical behavior for handling free variables with the barrier algorithm.
• Fixed an issue in which a user function was not provided the context pointer.
• Fixed an issue that could cause IIS to crash.
• Fixed an issue with the analytic center presolver for MIPs, which could result in data corruption, when Barrier is used in the tree and fails to solve a node relaxation.
• Fixed an issue with presolve implications when represolving a MIP, which could result in invalid solutions being returned.
• Fixed an issue in the storage of branching history information that could affect performance.
• Fixed an issue in conflict analysis that could potentially cause too short conflicts.

Xpress Nonlinear 35.01.05

• New XSLP_NLPSTATUS for capturing solve failiures, XSLP_NLPSTATUS_UNSOLVED.

Fixed in Release 8.8.3

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Xpress Optimizer 35.01.04

• Added support for Python 3.8 in the Xpress Python interface; support for Python 3.4 was dropped. Python 2.7 is still supported.
• A new control, CROSSOVERFEASWEIGHT, has been added to change crossover behaviour.
• Fixed and issue with handling of indicator constraints when presolve is turned off that could result in violated solutions being returned.
• Fixed an issue in implied entity detection if dual reductions are disabled
• Improved the deterministic timer for primal simplex.
• Fixed a performance issue with the diving heuristic for large MIPs with few non-binary variables.
• Fixed in issue in IIS that could cause a problem for infeasible MIP instances with range rows.
• Fixed an issue involving QCQP problems that are convertible to QP instances.
• Improved numerical behavior for estimaterowdualranges.
• Fixed an issue that could lead to SOS-constraint with non-positive variables being dropped in presolve.

Xpress Nonlinear 35.01.04

• Fixed an issue that could cause a crash when using XSLPchgccoef with longer than 500 token (string can be arbitrary long) formulas.
• Improved performance of postsolving dual solutions.

BCL 4.10.2

• Fixed possible memory leak when loading problems with both quadratic constraints and global entities or SOSs
• Fixed possibly wrong memory allocation size for loading names into the Optimizer when loading problems with more than 16M constraints or variables

Fixed in Release 8.8.2

Xpress Optimizer 35.01.03

• Fixed an issue that might cause reading incorrect memory areas when accessing a constraint in the Python interface.
• Fixed an issue that could cause crash when the barrier is executed with warm-start.
• Fixed an issue in presolve that could lead to returning infeasible solutions due to dropping wrong rows.

Xpress Mosel 5.0.3 Compiler Library

• Various minor fixes.

mmjobs 2.16.2

• Windows: a possible memory corruption has been fixed in the handling of the 'mempipe' driver.

mmnl 2.0.1

• Invalid assignments now report a runtime error.

mmsystem 2.6.3

• 'newtar' no longer generates an invalid archive with some large directory names.

mmxprs 2.20.2

• Invalid assignments now report a runtime error.

Workbench 3.2.3

• Fixed: Mosel processes not being cleaned up after running

Fixed in Release 8.8.1

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Xpress Optimizer 35.01.02

• Fixed an issue in the Python interface whereby integer variables are converted to binary variables.
• A new control, BARFAILITERLIMIT, has been added to limit the unsuccessful barrier iterations.
• Fixed a memory leak in the loadproblem() method of the Python interface.
• Fixed an issue in the dual simplex that could cause cycling in Phase 1.
• Range row support added to XPRSalter.
• Fixed a potential memory leak on Windows.
• Fixed an issue in presolving that could lead to a wrong sign for added inequalities.
• Fixed an issue with advanced presolving of MIPs that could result in a memory corruption.

Xpress Mosel 5.0.2 update mmhttp 2.6.1

• When sending a query use the 'origin-form' for the query line (some buggy servers do not support 'absolute-form').

mmjobs 2.16.1

• A submodel can no longer be marked as not running while the corresponding end-event is not yet available.

mmrobust 1.4.1

• Support for memoryuse.

New in Release 8.8

_{Back to top} Xpress Optimizer 35.01.01

• The Solution Refiner now includes an additional option to apply Iterative Refinement. Iterative Refinement involves shifting and rescaling of the problem between iterative solves of an LP, in order to improve a linear solution. It is based on the work described in "Iterative Refinement for Linear Programming, A.M. Gleixner, D.E. Steffy, K. Wolter, ZIB Report 15-15 (May 2015)". New bits have been introduced for the REFINEOPS control for Iterative Refinement:
  • bit 5: Enable iterative refinement
  • bit 6: Use quad precision when updating the solution.
• Memory reporting attributes have changed:
  • CURRENTMEMORY: Now reports on memory used by all objects part of the current problem solve, instead of just the queried object.
  • TOTALMEMORY: New control that reports on the total memory used by all solver objects. This includes Nonlinear and BCL.
• It is now possible to impose memory limits on a solve. New controls have been introduced:
  • MAXMEMORYSOFT: Adjust solver behavior to stay within the given limit (not guaranteed)
  • MAXMEMORYHARD: Terminate a solve if this limit is breached. The solver will return in an interrupted state that can be resumed and where solution information is available.
  • RESOURCESTRATEGY: A new bit-vector control. If bit 1 is set, then the solver is allowed to make a non-deterministic choice based on MAXMEMORYSOFT.
• A new control, MIPDUALREDUCTIONS, has been introduced, which can be used for disabling all dual related reductions throughout a MIP solve. This is particularly useful for users who do their own constraint generation or branching inside callbacks. This avoids having to turn off individual reductions that assume all constraints and the objective function are described completely as given in the initial formulation.
• It is now possible to work directly with individual bits of bit-vector controls in the Tuner. When listing bit-vector controls in a method file, use ":" instead of "=" when specifying bits instead of values to use.
• Added support for extended modelling information when reading LP and MPS file formats.
  • Added support for piece-wise linear objective functions and constraints.
  • Added support for general constraints: MIN, MAX, ABS, AND, OR
  • All such extended modelling information is converted into a linear continuous or MIP equivalent formulation at read time, potentially by introducing new constraints and variables.
• Improved crossover and simplex performance for large scale LPs.
• Presolve clique lifting and clique cutting for MIPs has been rewritten to remove scalability issues.
• Fixed several MIP performance issues for very large problems.
• Minor changes:
  • Two controls have been added for ignoring detected process control group limitations (e.g. used in "Containers") in Linux: IGNORECONTAINERSPULIMIT and IGNORECONTAINERMEMORYLIMIT
  • Extended the detection of Linux control groups (v1) to recognize more system configurations.
  • All coefficients are now written to and read from LP and MPS files exactly, meaning that when a coefficient is written to an LP/MPS file and read back in again, the exact same coefficient is recovered. This obsoletes the "z" option for the MPS file format.
  • Files written to the LP file format will now include a line identifying the version of Xpress it was written with.
  • The LP file format now supports unlimited line lengths.

Optimizer Python Interface

• The Python interface has now a much more flexible problem.getSolution() function for evaluating expressions and aggregate Python objects.
• Optimization problems can be specified in a compact way in the Python interface by inserting variables, constraints, and the objective function in the xpress.problem() call.
• A much smaller memory footprint for the Python interface's modeling feature. The amount of memory required for allocating variables and constraint is substantially reduced.

Xpress Nonlinear 35.01.01

• Redesigned formula handling when using mmxnlp:
  • Decreased memory usage when building expressions using 'nlctr' objects embedded into one another.
  • Decreased memory usage when generating identical 'nlctr' expressions.
  • Decreased peak memory usage when Mosel loads a problem.
• Improved the nonlinear eliminator in the nonlinear presolver.
• Nonlinear liminations are now enabled by default.
• Support for models with more than 2^31 nonlinear tokens.
• Parallel evaluations support for expensive blackbox functions in embedded expressions:
  • Blackbox functions depending on one another can now calculate their partial derivatives in parallel.
  • New callback 'PREUPDATELINEARIZATION'.
• New nonlinear primal integral support:
  • New attribute XSLP_PRIMALINTEGRAL' and 'XSLP_PRIMALINTEGRALFACTOR'.
• Nonlinear license will now be checked from Mosel only at the time of loading or solving a problem.

Xpress Mosel 5.0.2 mmnl 2.0.0

• Improved handling of quadratic expressions.
• Support for += and -= (that preserve constraint direction).

mmoci 1.8.1

• In debug mode a warning is now displayed when strings are truncated.

mmodbc 3.6.0

• mmsqlite driver: new option 'timeout' to define the busy timeout.
• In debug mode a warning is now displayed when strings are truncated.

mmsystem 2.6.2

• 'formattext' is no longer limited to 64k text strings.

mosjvm 1.0.13

• Now supports Amazon Corretto JVM.

python3 2.0.1

• The latest supported Python version is 3.7.5. Python 3.8.0 is not supported (https://bugs.python.org/issue37633).

Workbench 3.2

• New Mosel syntax analysis to highlight errors in source code.
• The Outline pane now works on Mosel files, as well as Javascript, and allows to jump to definition.
• View Designer
  • Now highlights when the element hierarchy on the page breaks soft validation rules.
  • Attribute values are visible in the attributes pane when attribute is set to default
  • Element selection no longer writes a placeholder attribute into the VDL code.
  • Attributes are now organized into collapsible groups.
  • When selecting an element in the View Designer and then switching to the code editor, the code editor will jump to the selected element source
  • Copy/cut/paste operations via the clipboard are now supported in the View Designer
  • New project preference for selecting code editor or View Designer as default editor for VDL files

Xpress Kalis 12.7.0

• Xpress Kalis is now available for MacOS.
• The Commmunity Licence now enables a size-limited version of Xpress Kalis.
• New procedure 'setsetuptime' to specify a setup time between two tasks iff they both require the same resource.
• New function 'dot' for efficient computation of the scalar product between an array of decision variables and an array of numbers.

Fixed in Release 8.8

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Xpress Mosel 5.0.2

mmxprs 2.20.1

• Memory usage information can now be retrieved from within a callback.

mmodbc 3.6.0

• Fix for multiagg issue with median calculation on sample-weighted data.

Xpress Kalis 12.7.0

• Fix integer overflows in cumulative resource constraint usage.
• Fix return value of 'cp_schedule' when 'kalis_max_solutions' set to 1 and solution is suboptimal.
• Various minor memory issues and bug fixes.

• The Xpress Kalis examples 'runfapp[r].mos' fail to run properly under Linux.

Fixed in Release 8.7.3

Xpress Optimizer 34.01.09

• A new control, CROSSOVERFEASWEIGHT, has been added to change crossover behaviour.
• Added support for Python 3.8 in the Xpress Python interface; support for Python 3.4 was dropped. Python 2.7 is still supported.
• Fixed an issue that could cause crash when the barrier is executed with warm-start.
• Fixed an issue with advanced presolving of MIPs that could result in a memory corruption.
• Fixed an issue in presolve that could lead to returning infeasible solutions due to dropping wrong rows.

Fixed in Release 8.7.2

_{Back to top} Workbench 3.1.2

• Fixed: when publishing, Workbench would not recompile the model if an included source file was modified.
• Fixed: Workbench did not start up if home directory was unavailable.
• Fixed: model schema did not appear in view designer for some models.

Fixed in Release 8.7.1

_{Back to top} Xpress Nonlinear 34.01.07

• Fixed an issue in nonlinear formula eliminations in the nonlinear presolver.
• Limited the number of automatically allowable step bound repaired infeasible iterations.

Xpress Mosel 5.0.2 mmodbc 3.4.1

• Fix for multiagg issue with median calculation on sample-weighted data.

New in Release 8.7

_{Back to top} Xpress Mosel 5.0.2 moseldoc 1.4.1

• Tabulations can now be used to separate fields in documentation annotations.

mmxprs 2.20.0

• Optimizer problems are now created when used (e.g. to load the problem into the solver).
• The Optimizer library is now initialized just before creating the first Optimizer problem.

mosjvm 1.0.12

• Java threads are automatically attached to the Mosel thread on first call, and detached when the thread ends; it is no longer necessary to call jvmattachthread/jvmdetachthread to achieve optimal performance.
• Support calling Java methods with variable numbers of arguments (Varargs methods).

Xpress Workbench 3.1.0

• New view designer for authoring VDL views.
  • Drag and drop artboard for designing the view
  • Elements palette and attributes pane for simple access to most VDL features
  • Wizards for accelerating common actions
  • Wizards for implementing logic rules
  • Switch between artboard and code editor views seamlessly
• New wizard for creating VDL views.
• New pane for managing Insight views and view groups.
• Improved launch screen with examples browser.
• Improved Mosel compilation messages.
• Fast incremental publish to Insight, includes only files that have been modified since last publish.
• Support for Insight 4.51.
• Support for VDL 4.6.
• Updated VDL examples to version 4.6.

Fixed in Release 8.7

_{Back to top} Optimizer Python Interface

• Fixed an issue in the Python interface for solving quadratic nonconvex problem with a maximized objective function.
• Fixed an issue in the Python interface that may prevent writing to file a linear problem if a nonlinear license is present.

Xpress Nonlinear 34.01.05

• Fixed a problem in which multistart would ignore a timeout.

Xpress Mosel 5.0.2 Compiler Library

• An issue has been fixed in the handling of overloading subroutines between packages and modules.

Runtime Library

• Options of driver 'raw:' are now properly identified.

mmsystem 2.6.1

• Function 'jointext' now handles properly empty strings.

R 1.1.2

• Fixed an issue with the optimized Rset that searched simple identifiers not only in the current GlobalEnv but also in enclosing envs.

Xpress Workbench 3.1.0

• When connecting to Insight over HTTPS, certificates from the OS keystore are now used to verify the server.
• Parameters provided when running a Mosel model now interpret single and double quotes correctly.
• Project would fail to publish to Insight if the path contained a single quote character.
• Index set names are now shown correctly when displaying array variables with single-character names in tables.
• Intermittent glitches were present in the folder dialog when creating or opening a project.
• Mosel source files were not detected if the path to the project contained a dollar symbol.
• Environment variables can now be passed to Mosel models on macOS.

Licensing (xprl) 3.0.4

• Fixed an issue with the 'xphostid' tool on some non-English installations of Windows.
• Fixed an issue running the license server as a Windows service using the non-default account.

New in Release 8.6

_{Back to top} Xpress Optimizer 34.01.03

• Information is now available in the log about numerical considerations of a problem being solved:
  • Information about the range of coefficients in the matrix, the objective and the right-hand side will now be printed at the start of any solver.
  • If numerical issues were encountered during a solve, a summary will now be printed at the end of the solve.
  • A new control, MIPKAPPAFREQ, as been introduced to allow for the sampling of the condition number (Kappa) of the LP bases encountered during a MIP solve. A summary will be printed at the end of the solve.
• All memory usage by the Optimizer, SLP and BCL is now being tracked and is reported through the following attributes:
  • SYSTEMMEMORY - Memory not associated with any particular problem instance, such as that used by the global environment.
  • CURRENTMEMORY - Current memory usage by the problem that the attributes is queried against.
  • PEAKMEMORY - Peak memory usage by the problem that the attribute is queried against.
  • Added support for Linux control groups (e.g. Docker containers) for memory and core restrictions. These will be used for limiting the memory usage by the Optimizer and for setting a thread limit. Restrictions will be checked at initialization time (XPRSinit) only.
• The API recorder for capturing all Optimizer API library calls has been extended to record all SLP and BCL API library calls.
• Numerical behavior of the Barrier algorithm has been improved, in particular for quadratic/conical problems and for variables with very negative lower bounds.
• Local search heuristics are now applied more frequently during root processing of MIPs and will also be run, by default, before or during cutting.
• More types of rounding heuristics are now run during root cutting or during the branch-and-bound tree search.
• A new control, PRECONVERSEPARABLE, has been introduced to enable the reformulation of quadratic constraints as second order cones. This reformulation significantly improves performance on Mixed Integer Quadratically Constrained Quadratic problems. The control is on by default when Outer Approximation is used.
• It is now possible to scale the objective function of MIPs, by setting the OBJSCALEFACTOR control to the desired scaling factor.
• A new tuner method has been added to the TUNERMETHOD control (value 8), which focuses on tuning heuristic performance.
• Several changes to improve performance on MIP problems.
• Minor changes:
  • A new callback, checktime, has been introduced for MIP solves, which will be fired when the solver deterministically checks for the time limit. It can be used for interrupting a solve.
  • A new callback, presolve, has been introduced, which will be fired immediately after a problem has been presolved.
  • New attributes, PHYSICALCORESDETECTED and PHYSICALCORESPERCPUDETECTED, are now available for obtaining the number of physical cores detected in the host system, or the number of physical cores per cpu, respectively.
  • New control REPAIRINFEASMAXTIME to limit the overall time spent when calling XPRSrepairinfeas.
  • New control ELIMFILLIN to limit the amount of fillin for individual variable eliminations during presolve.
  • New string attribute UUID that returns a 32 hexadecimal digit string containing a Universally Unique Identifier associated with the given problem. The UUID is automatically appended to the name of any global file created during a MIP solve of the problem.
  • New bit-vector control LPFLAGS to specify the algorithm(s) to use when solving an LP or the initial LP relaxation of a MIP. This control can be used instead of passing the "p", "d", "b" or "n" flags to XPRSlpoptimize or XPRSmipoptimize.
  • New API function XPRSsaveas(), similar to XPRSsave(), but which now accepts a filename.
  • The LP format file reader now accepts arbitrary line lengths. The LINELENGTH control is now deprecated.
  • Searching for an Irreducible Infeasible Set (IIS) for MIPs has been made more efficient.

Optimizer Python Interface

• Improved speed and memory performance.
• Added support for Python 3.7.
• Added model, solver, and interface exception types.

Xpress Nonlinear 34.01.03

• Improved network support in SLP through determining rows, targeting very large problems over a network structure.
• Adaptive SLP iterations targeted at numerically difficult instances .
  • New string control 'XSLP_ITERFALLBACKOPS'
  • The Optimizer API recording facility has been extended to record all Nonlinear library API calls, including the recording of user functions.
• New API function to load user functions:
  • XSLPadduserfunction
  • XSLPdeluserfunction
• New API to load external libraries, designed to be used within user functions:
  • XSLPimportlibfunc
• New initial point heuristics targeted at scenario exploration.
• Automatic detection of doubleton eliminations connecting cascaded rows.
• Odd integer roots negative numbers are now supported.
• Added support for the error function and its complement: 'erf' and 'erfc'.

  Deprecated in this release: XSLPsetcbformula, XSLPsetfuncobject, XSLPsetstring, XSLPsetuniqueprefix, XSLPsetuserfuncaddress, XSLPsetuserfuncinfo, XSLPsetuserfuncobject, XSLPtime, XSLPtokencount, XSLPuserfuncinfo, XSLPvalidformula, XSLPaddcvars, XSLPaddnames, XSLPadduserfuncs, XSLPdelcvars, XSLPdeluserfuncs, XSLPfilesol, XSLPformatvalue, XSLPloaduserfuncs, XSLPparsecformula, XSLPparseformula, XSLPpreparseformula, XSLPprintmsg, XSLPqparse, XSLPgetcoefs, XSLPgetcvar, XSLPgetdtime, XSLPgetfuncinfo, XSLPgetfunctioninstance, XSLPgetfuncobject, XSLPgetmessagetype, XSLPgetnames, XSLPgetparam, XSLPgetrowinfo, XSLPgetstring, XSLPgettime, XSLPgetuserfunc, XSLPgetuserfuncaddress, XSLPgetuserfuncobject, XSLPgetversion, XSLPcalluserfunc, XSLPchgcvar, XSLPchgfuncobject, XSLPchguserfunc, XSLPchguserfuncaddress, XSLPchguserfuncobject.

Xpress Mosel 5.0

• Packages are now handled like native modules: they are loaded dynamically at runtime when the model is loaded into memory. They can also define control parameters that are accessed via 'setparam' and 'getparam'.
• This new handling of packages required a significant revision of how Mosel manages memory and the bim file format itself had to be redesigned. Because of these changes this new version of Mosel cannot use packages compiled with other releases and it can only run model bim files produced by Mosel 4.2 and newer.
• The implementation of arrays has been revised: a static array is now always dense even if its indexing sets are not constant. It is therefore no longer possible to use a static array indexed by non-constant sets as a dynamic array.

Language

• A set can now be declared as 'dynamic' (e.g. S:dynamic set of integer): sets defined this way cannot be finalised
• Support for namespaces: new statements 'namespace','nssearch','nsgroup'
• Initialisations blocks can export or import an entire namespace from its name
• New option 'tagpriv' to prefix local symbols with '~' (models only)
• New option 'dynonly' to disallow static linking of a package
• 'uses' applied to a package no longer imports it in a model: the package remains a requirement for the model that will be imported when the model is loaded
• Packages can now define control parameters that are accessed using 'getparam' and 'setparam'
• Lists can now be dereferenced: l(1) is equivalent to getfirst(l) and l(0) is the same as getlast(l), l(-1) is the element before the last one etc.
• 'list(s)' creates a list from set s and 'set(l)' creates a set from list l
• 'list(l)' returns a copy of list l and 'set(s)' returns a copy of set s
• New functions cutelt(l,n), cutfirst(l), cutlast(l) to extract the nth, first and last element of a list; cutfirst and cutlast can also be applied to a range
• New function getelt(s) to get an element from a set or list
• New function cutelt(s) to get and remove an element from a set or list
• If T is a type name and IT an instance of this type then T(IT) returns a copy of IT (i.e. clone operator)
• A record entity can now be created and initialised using the syntax: recnam(.fl1:=v1,.fld2:=v2...) where 'recnam' is the type name and fldi one of its fields
• New compiler annotation '@mc.dbgmsg' to send a notification to the debugger:

  !@mc.dbgmsg break      to suspend execution and trigger debugger
  !@mc.dbgmsg traceoff   to disable tracing
  !@mc.dbgmsg traceon    to (re)enable tracing
  !@mc.dbgmsg tracelog   to log a message in the trace file

• 'exportprob': new option EP_HEX to generate an MPS hexadecimal matrix file
• New procedure 'setrange' to create range constraints
• New procedure 'getcoeff(ctl,int)' to retrieve range information
• New control parameter 'runparams', the parameters received by the model
• New control parameter 'bimprefix' to define a list of bim prefixes
• Procedure 'reset' can now be applied to sets,lists and arrays
• New function 'memoryuse' to report current memory use (model, entity or a module)
• New functions 'versionnum/versionstr' to retrieve version of Mosel and modules/packages being used by the running model
• New array type 'hashmap' (similar use as 'dynamic')
• 'initialisations from/to' and 'fopen' can now take any type supporting stringification (like 'text') for file name
• Declaration of subroutines can now be done in 'declarations' blocks:

  declarations
    procedure myproc(i:integer)
  end-declarations
  ! is equivalent to:
  forward procedure myproc(i:integer)

• New procedures 'localsetparam' and 'restoreparam'
• Procedure 'publish' can now be use with a string as its second parameter
• Function 'datablock' to embed data files in bim files
• All predefined routines can now be overloaded
• Numeric constants can nom be expressed in hexadecimal

mosel

• New 'examine' option 'L' to load dependencies
• New command 'trace' and execution option '-trac' to execute a model in tracing mode
• New option '-tr fn' to define the name of the trace file (or env. variable MOSEL_TRFILE)
• Deprecated command line option '-c' no longer supported
• Option '-bx' now takes a list of prefixes (separated by '||') and can now be used with all commands (like -dp)
• Options '-dp' and '-bx' can be stated several times (values are concatenated)

Remote invocation

• New command 'profrep' (to generate result file after profiling/covering)
• New runmode '3' to generate a trace file
• New control 'bimprefix' to define the global list or bim prefixes

Runtime Library

• 'getmodprop': new property 'NBBIM' (the number of bim files)
• 'getmodprop': higher 16bits to select the bimfile
• 'loadmod' now loads required packages when loading a package
• 'loadmod' new option 'l' (lazy) to avoid loading dependencies of a bim file
• New function 'getnextmoddso' to get list of used dso by a model
• New function 'getnextpkgparam' to get list of parameters of a package
• Improved handling of large constraints
• New functions 'setbimprefix/getbimprefix' to set/get default bim file prefixes
• bim files can now be loaded from a path in the 'dsopath' when the instance does not have read access under restriction
• The runtime parameter string is now more rigorously checked
• Functions getsetsize,getlistsize and getarrsize now return an unsigned integer
• The default value for realfmt is now "%.10g" (was: "%g")

Compiler Library

• Private symbols are no longer included by default (need to use -g)
• Option '-s' (strip) no longer supported (silently ignored)

Native interface

• New service SRV_NSGRP for defining namespace groups from a module
• New function 'getnextmoddso' to get the list of used dso
• New functions 'getnextanident' and 'getannotations'
• New function 'delarrcell' to delete a cell or reset a dynamic array
• New flag 'MM_FTYP_PTR' for function type to indicate that the function is returning a pointer to an existing entity (i.e. this is not a constructor)
• New function 'getvcinfcause' to report the cause of a loadmatrix failure
• New service 'SRV_MEMUSE' to report memory usage
• New function 'memoryuse' to get memory usage of an entity
• New function 'clsarrsrtndx' to clear sorted indices of a hashmap array
• New file operation 'IOCTRL_SIZE' to return the size of a file
• Function 'fsize' to get the size of a file
• 'fopen' function of an I/O driver receives now an additional parameter to set the buffer size
• Native routines can now return sets or lists
• 'setdsoparam' now automatically converts the parameter value to the expected type
• New function signature '?' (accepts an argument of any type)
• Functions getsetsize,getlistsize and getarrsize now return an unsigned integer

XPRNLS

• XNLSopenconv: internal buffer size can now be set using macro XNLS_OPT_BSZ

mmhttp 2.6.0

• Support for cookies (client): http_cookies,savecookies,loadcookies,delcookies,setcookie,findcookie
• Support for cookies (server): mksetcookie,httpreqcookies
• New parameter 'http_freeasync' reporting the number of available asynchronous slots
• 'httpreqfrom' and 'httpreqlabel' now return a text (instead of a string)

mmjobs 2.16.0

• Support for 'getfsize' on 'shmem:' and 'rmt:'
• New procedure 'waitforend' to wait for termination of a model
• New functions 'getdsopropnum','getmodpropnum' to retrieve numerical properties as reals (instead of strings)
• rmt driver: buffer size can now be changed (from 2k to 64k)
• [re]setmodpar routines can now be used with text parameter names
• compile/load/connect can now be used with text parameters

mmnl 1.10.0

• Improved handling of runtime constants in expressions

mmoci 1.8.0

• OCIlogon can now be used with 'text' instead of 'string'

mmquad 1.4.0

• MPS format: support for EP_HEX
• Improved handling of large quadratic expressions

mmsheet 1.6.0

• Support for 'fgetsize' applied to an open file
• New CSV option 'alltxt' to disable type detection

mmssl 1.4.5

• Improved error detection in the base64 IO driver

mmsystem 2.6.0

• 'getfsize' can now be used with extended file names
• 'sysinfo' now also report total amount of system memory (SYS_RAM)
• New option 'SYS_FLAT' for 'untar' and 'unzip'
• New routines setoserror,getoserror,getoserrmsg,erase
• New function jointext and splittext
• New time formats '%f' and '%F' for milliseconds processing
• New routines 'getdsoparam' and 'setdsoparam'

mmxml 2.2.5

• Namespace prefixes can now be used in search paths

mmxprs 2.18.0

• New procedure 'readsol' to load an mpsol from a file
• The matrix is no longer reloaded when only the objective has been updated and it is of type 'qexp' (full reload still occurs with 'nlctr' objectives)
• PREINTSOL callback now requires an integer as its first parameter (instead of a boolean before)

python3 2.0.0

• Update requirements: Models that have been compiled with Mosel 4 and use python3, have to be recompiled with Mosel 5.
• Support for pandas DataFrame, pandas Series, NumPy ndarray, and NumPy scalar types.
• Support for Mosel text type conversion.
• New parameter 'pyusepandas' for choosing Python target type for Mosel array conversion.
• New procedure 'pyinitpandas' to initialize pandas interface.
• New routine family 'pycall*' to call a Python function with input arguments and get the return value.
• New routine family 'pyget*' to evaluate a Python expression and get the return value.
• New procedure 'pygetdf' to initialize a list of Mosel arrays from a pandas DataFrame.
• New procedure 'pyset' to assign a Mosel value to global Python variable.
• New procedure 'pysetdf' to assign a list of Mosel arrays to a pandas DataFrame.
• Support empty file name in I/O driver to access global Python variables: "python:".
• Support Python string evaluation in "initializations from" blocks when extended file name is "python:".

R 1.1.01

• Added 'Rsetdf' function
• Added 'syncwritecon' parameter to enable synchronization in the 'WriteConsole' callback
• Improved evaluation speed for R expressions consisting of a single simple identifier
• Default R installation locations for 64bit Linux now include both /usr/lib64/R and /usr/lib/R
• Mosel security restrictions check is delayed to R init time (instead of module init time)
• Improved handling of R factors with faster conversion to Mosel strings

mosjvm 1.0.11

• Parameters relating to JVM startup are now shared by all models in the Mosel process.
• New parameter "jvmloaded" for checking if the JVM has already been loaded.
• Now supports Java 8 and Java 11.

Xpress Workbench 3.0.2

• Support for Mosel 5 and Insight 4.50.
• New module browser sidebar shows all Mosel modules and their exported symbols.
• Inline documentation is now shown when autocompleting symbols from Mosel modules.
• Improved autocompletion of Mosel statements.
• Mosel models can now be run in trace mode.
• Bim files are now compiled into an output folder in the project, by default /out, and the master bim file is copied into the root of the archive only on publish or download app. Therefore any legacy bim file in the root of a project is obsolete and should be deleted to avoid confusion.
• When compiling a Mosel model, the directory where bim files are created can now be specified.
• New module browser sidebar shows all Mosel modules and their exported symbols.
• Inline documentation is now shown when autocompleting symbols from Mosel modules.
• Improved autocompletion of Mosel statements.
• Mosel models can now be run in trace mode.
• When compiling a Mosel model, the directory where bim files are created can now be specified.
• When connecting to Insight over HTTPS, certificates from the OS keystore are now used to verify the server.

BCL 4.10.0

• Integrated BCL into the Optimizer library (linking of xprb is no longer required)
• The .Net class XPRBprobStruct has been obsoleted

Xpress Kalis 12.6.3

• Added a 'table_constraint' which implements a Generalized-Arc-Consistency Table constraint.

Fixed in Release 8.6

_{Back to top} Xpress Workbench 3.0.2

• Fixed an issue where externally edited files were being overwritten by Workbench when autosave is enabled.
• Fixed an issue where updated Mosel model would not be published to Insight if a bim file already exists.
• Fixed an issue where the debugger will not connect if the Workbench window is too narrow.
• Fixed an issue where directories within a Workbench project cannot be deleted or renamed when the project is open.
• Fixed an issue on macOS where Mosel models cannot be run when the project path is too long.
• Fixed an issue where error messages printed by submodels are not displayed when the master model is run in Workbench.
• Fixed an issue where interrupting an Insight debug session would leave the scenario executing until manually cancelled from the Insight job queue.
• Fixed an issue where Workbench could hang when the .c9 directory was not present in the home directory.

BCL 4.10.0

• Fixed C++ disabling of implicit XPRBprob copy assignment operator
• Fixed .Net setObj(XPRBexpr) method to prevent the expression to be garbage-collected while still in use

Xpress Kalis 12.6.3

• Fixed bug in relaxation framework.
• Other minor memory issues and bug fixes.

_{Back to top}

• When using the mmodbc module to access a MySQL database on macOS, we recommend using MySQL Connector/ODBC version 5.2, as 5.3 and 8.0 can silently fail to perform bulk updates due to MySQL bug #95608.

Fixed in Release 8.5.11

_{Back to top} Xpress NonLinear 33.01.13

• Made bound reduction less sensitive toward extreme bounds in log() and log10() functions.
• Improved initial point heuristics with cascading.
• Fixed a potential issue when runing parallel MISLP with Mosel user functions.
• Improved initial point heuristics.
• Improved cascading logic for network structures.
• Support Mosel user functions returning partial derivatives with variable argument lists.
• Off-scale bounds due to functions such as exp() now trigger a warning rather than infeasibility.
• New public control XSLP_DELTA_INFINITY to limit placholders taking exceedingly large values.
• Fixed in issue with the multistart search when using initial values from Mosel
• Fixed an issue with eliminations on singleton rows.

New in Release 8.5.6

_{Back to top}

Xpress Mosel modules

mosjvm 1.0.7

• Allow option to run any classes in restricted mode by setting MOSJVM_ALLOW=*
• Allow jvmclasspath parameter to be set in restricted mode

dmp 1.0.0

• New module to allow models running in DMP to call other DMP resources in solution

executor 1.0.4

• When running within DMP, authorization will no longer expire after 1 hour
• Failed HTTP requests will now be retried

Fixed in Release 8.5.6

_{Back to top} Xpress Nonlinear 33.01.09

• Fixed an issue with eliminations on singleton rows.
• Fixed a memory leak that could occur when repeatedly restoring and presolveing a problem.
• Calling XSLPglobal now resets the solve timer.
• Fix incorrect header in save files.
• Support cubic root of negative numbers.

Xpress Mosel modules mmhttp 2.4.4

• An issue has been fixed in the handling of the connection pool

mmsystem 2.4.5

• 'fcopy' with 4 arguments now closes all its streams after an error

Xpress Workbench 2.2.4

• Added cancel button to progress dialog shown when publishing to Insight.
• Fixed an issue where the progress dialog sometimes got stuck when publishing to Insight.
• Fixed an issue where error messages were not displayed after disconnecting from a child instance of Mosel.
• Fixed an error, "Cannot read property 'getDocument' of undefined" when saving a tab which is not fully loaded.

Licensing (xprl) 2.9.7

• Fixed an issue that caused creation of xprl.log files on Windows

New in Release 8.5.3

_{Back to top} Xpress Nonlinear 33.01.05

• More agressive ERRORCOST updates for unbounded problems.
• New convergence option XSLP_CONVERGEBIT_NOQUADCHECK.
• Improved convergence criteria for mixed convex quadratic and nonlinear problems.

Xpress Mosel 4.8.4 mmhttp 2.4.3

• HTTP server now rejects invalid queries

mmsystem 2.4.4

• Posix: better handling of quotes in the processing of the 'system' command

Xpress Workbench 2.2.2

• BETA support for macOS
• Clicking a line in a Mosel stack trace opens the correct source file location.
• Subprocesses executed from Mosel inherit the correct working directory specified in Workbench.
• When autocompleting the name of a subroutine from a Mosel package or module, all available subroutine signatures are now shown.

Fixed in Release 8.5.3

_{Back to top} Xpress Nonlinear 33.01.05

• Fixed a potential issue when solving problems with integer delta variables.

Xpress Mosel 4.8.4 Compiler library

• An issue has been fixed in the handling of file inclusion

mmsheet 1.4.6

• xlsx/xls/csv: an issue has been fixed in the conversion of Booleans to text

Xpress Workbench 2.2.2

• Fixed an error when downloading very large arrays as CSV.
• Fixed an issue where Mosel error messages where not clickable when they wrapped onto a new line.
• Fixed an issue where relative source file paths passed on the Workbench command line were not correctly located.
• Fixed an issue where incorrect file tree was sometimes shown when several workspaces were open at the same time.
• Fixed an issue where 'Show item in Explorer' stopped working after compiling a model.

Known issues on macOS:

• Dialog appears intermittently while editing source files: "File has been changed on disk."
• Not possible to set environment variables when running Mosel models.
• Workbench does not detect changes to the environment, e.g., XPRESSDIR, after being restarted.

New in Release 8.5

_{Back to top} Xpress Optimizer 33.01.02

• Symmetries may now be re-detected locally during a MIP tree search when it is determined to be beneficial.
• Improved branching for highly symmetric MIP problems.
• Improved zero-half cuts, in particular for binary quadratic problems.
• New multi-commodity network flow cuts. A new control, NETCUTS, has been introduced for these cuts.
• Improved dual simplex perturbation scheme for highly dual degenerate MIPs.
• Improved performance of crossover through better exploitation of vectorization and CPU caching.
• New API functions XPRSgetlpsolval, XPRSgetmipsolval and XPRSgetbasisval for retrieving the solution value or basis status for an individual variable or constraint.
• Two new controls, PRIMALPERTURB and DUALPERTURB, have been introduced to replace the single PERTURB control. Perturbation can now be controlled separately for primal simplex and dual simplex.
• A new control, PRESOLVEPASSES, has been introduced to allow repeated applications of the initial preprocessing of a problem.
• The obsolete control TEMPBOUNDS has been removed.
• All fixes from Xpress Update 8.4.7 (Optimizer 32.01.10).

Xpress Nonlinear 33.01.02

• Improved MINLP rounding heuristics.
• Improved SLP-MIP-SLP heuristics in case some rows are enforced in the first SLP iteration.
• All fixes from Xpress Update 8.4.7 (Nonlinear 32.01.10).

Xpress Mosel 4.8.3 Native interface

• Function 'copyval' can now be used with STR_SET, STR_LIST and STR_ARR

mmhttp 2.4.2

• New function 'tcpping' to test a server
• Unauthorized urls in FAC are now reported as error 997 (execution is no longer interrupted)
• Support for SNI (server name identification) in https

mmsheet 1.4.5

• Excel driver: better handling of files stored on network drives

mmssl 1.4.4

• Updated version of ca-bundle.crt
• New driver 'hmac'

mmsystem 2.4.3

• Comparison operator has been added to 'time', 'date', 'datetime' and 'text' to enable comparison of records or arrays including these types

mmxprs 2.16.0

• New procedure 'loadlpsol' to load LP solutions for barrier warm start and crossover
• New procedure 'crossoverlpsol' to cross over a loaded LP solution
• New procedure 'uselastbarsol' to retrieve a barrier solution from before crossover
• Parameter 'xprs_objsense' can now be changed

python3 1.0.0

• Execute Python 3 scripts from Mosel
• I/O driver 'python' for exchanging data using 'initializations from' and 'initializations to'
• Supported on Windows, Linux, MacOS

aec2 2.0.0

• Now a pure Mosel package (aec2 and smew modules dependencies have been removed)
• Support for Amazon signature protocol v4

Xpress Workbench 2.2.0

• When debugging, Mosel arrays, sets and lists can be displayed in table form, where they can be sorted/filtered.
• When debugging, Mosel arrays, sets and lists can be exported in a CSV file.
• Added a compile button to the toolbar.
• Mosel compiler options can now be specified.
• Mosel models can be run with profiling or coverage enabled.
• Improved support for Mosel DSO data types in the debugger.
• Added a context menu item in the editor to find all usages of the selected model symbol.
• After running or compiling a model, the output pane is now automatically shown, if it was hidden.
• Workbench now looks in the MOSEL_DSO environment variable when searching for Mosel package dependencies.
• Compiler uses MOSEL_DSO environment variable to find dependencies
• Workbench now integrates with the online help system

BCL 4.8.14

• Updated.Net Scanner class to support exponential notation

Fixed in Release 8.5.0

_{Back to top} Xpress Mosel 4.8.3 Compiler Library

• An issue has been resolved in the handling of assignments of loop indices referring to external types
• 'initialisations' blocks no longer accept lists of arrays of user types (this is not supported)

Runtime Library

• A possible memory corruption has been fixed in the handling of list concatenation when the first list is empty

mmsystem 2.4.3

• An issue has been fixed in untar/unzip related to handling of directory names
• 'setenv': removing an environment variable by giving it an empty value now always works

R 1.0.14

• Fixed an issue with models that use the I/O driver without initializing R

Xpress Workbench 2.2.0

• Fixed an issue where opening a second Workbench could hang on the loading screen.
• Fixed an error, "Current scheduler state does not fix stack level", shown when stepping in the debugger.
• Fixed an issue where the watches tree would collapse when inspecing a large array.
• Fixed a warning which occurs when many Mosel processes are created, "Possible EventEmitter memory leak detected".
• Fixed an error, "Step operation interrupted by debugger", which could occur when stepping over slow subroutine calls.
• Fixed incorrect label, "Select Folder to Upload", when creating or opening a project.
• Fixed error when opening projects stored on a drive other than C:
• Fixed issue where Mosel output contains unexpected symbols on Windows 7
• Fixed an issue where Mosel appears to hang and display no output when running a model
• Fixed issue where output pane would sometimes remain blank when publishing
• Fixed issue where watch tree collapsed immediately after being expanded

New in Release 8.4.4

_{Back to top} Xpress Mosel 4.8.2 XPRD

• Java: new field 'XPRD.rcmdEnv' to define environment variables in the environment of the process created via 'rcmd:'

Native interface

• New function 'setdsoparam'

mmodbc 3.2.3

• New version of SQLcolumns

mmjobs 2.14.1

• 'waitexpired' now returns 'true' when 'waitfor' has been called with a 0-time limit and no valid event was found

mmsystem 2.4.2

• New routines findfiles(findfiles(integer,list of text,text,text), findfiles(integer,list of text,text), findfiles(list of text,text)

mmxml 2.2.4

• Namespace prefixes can now be used in search paths

nlsolv 0.2.0

• New module to solve the problem with an AMPL-compatible solver

Fixed in Release 8.4.4

_{Back to top} Xpress Nonlinear 32.01.07

• Improved numerical stability for problems with a numerically difficult convex quadratic objective.
• Fixed an issue where an infeasible solution could have been returned.
• XSLP_VERSION and XSLP_MINORVERSION now returns the correct value.
• XSLP_ALGORITHM bit 6 'Reset XSLP_DELTA_Z to zero when converged and continue SLP.' now behaves as intended.
• Added support for using XPRSaddcols64 and XPRSaddrows64 together with XSLP.

Xpress Mosel 4.8.2 Runtime Library

• 'getnextattrdesc' no longer returns invalid type numbers
• Comparisons 'infinity=infinity' and 'infinity<>infinity' have been fixed

Compiler Library

• An issue has been resolved in the handling of empty statements in 'if' and 'case' conditions

mmjobs 2.14.1

• 'waitfor' may no longer miss an event with the expected properties when the option 'keep' is enabled
• A potential memory corruption has been fixed in the 'send' procedure when an event is sent to a terminating model

mmsheet 1.4.4

• csv driver: reading now stops when an out of memory error is detected

mmssl 1.4.3

• A potential memory corruption has been fixed in the 'sslrandomdata' function

mmsystem 2.4.2

• An issue has been fixed in the implmentation of "textfmt(real,int,int)"

Xpress Workbench 2.1.4

• Fixed issue where output pane would sometimes remain blank when publishing
• Fixed issue where watch tree collapsed immediately after being expanded
• On premises, the Mosel compiler now uses the MOSEL_DSO environment variable to locate packages and modules
• On premises, Workbench now integrates the online help site rather than the CHM version of the documentation

Licensing ( XPRL 2.9.1 )

• Fixed an issue re-establishing connection to license server after a network error.
• Fixed an issue with redundant server licensing when license server started with -d flag
• Corrected error message displayed when counted license checked out 60+ times

Xpress Kalis 12.6.2

• Fixed bug in 'produces' constraints

Fixed in Release 8.4.2

_{Back to top} Xpress Nonlinear 32.01.05

• Improved local search heuristics for MINLP problems.
• Improved relative infeasiblity checks when XSLP_FILTER bit 1 is enabled.
• The SLP iteration solution refiner will now check for change in relative primal infeasiblity.
• Added missing Knitro max nodes control export.
• XSLP_MIPITER now applies to the SLP-MIP-SLP and MIP-in-SLP heuristics as well.
• New fallback strategy for problems instable in linear presolve due to cascading structures.

Xpress Mosel 4.8.1 mmoci 1.6.1

• OCIcommit/OCIrollback do not set OCIsuccess

mmodbc 3.2.2

• SQLautocommit no longer ignored

Xpress Workbench 2.1.2

• Fixed errors when running Mosel models: "died waiting for dll loading, errno 11" and "Resource temporarily unavailable"

Fixed in Release 8.4.1

_{Back to top} Xpress Nonlinear 32.01.04

• Improved barrier fallback strategy for numerically instable solves.
• The drcoltol handler and callback are now initiated by XSLPcontruct if set up.

Xpress Mosel 4.8.1 Compiler Library

• An issue has been resolved in the handling of conversions in string concatenations.

mmhttp 2.4.1

• HTTP headers of responses are now case insensitive.

mmssl 1.4.2

• New default value for https_ciphers: "TLSv1.2+HIGH:TLSv1+HIGH:@STRENGTH"

Xpress Workbench 2.1.1

• Fixed issue where old backups were not being cleaned up properly

New in Release 8.4

_{Back to top} Xpress Optimizer/NonLinear 32.01.03

• It is now possible to exploit symmetries in LP problems using a procedure called LP Folding. This can significantly reduce the size of the problem to be solved and thereby speed up the solution process.
  • LP Folding is automatically applied and can be used with any LP solving algorithm.
  • A new control, LPFOLDING, has been introduced to specify whether LP Folding should be applied.
  • When LP Folding is applied a solve will now go through three phases: solve the reduced LP using the selected algorithm, a crossover phase and a final cleanup. The exception is when barrier is applied without crossover.
• For tiny MIP instances with integer or binary variables with a wide range of coefficients, it is now possible to apply a basis reduction algorithm as part of presolve, which will reformulate the integer columns using a reduced basis that is closer to ortho-normal. A new control, PREBASISRED, has been introduced to specify whether MIP basis reduction should be applied.
• More uses for the Barrier algorithm have been introduced as part of a MIP solution process. It can now be used for tightening or reducing the problems. A new control, PREANALYTICCENTER, has been introduce to specify when to use a Barrier solution.
• Several refinements to the branch-and-bound code to improve MIP performance.
• Output to the file created by XPRSsetlogfile is now flushed after each line.
• A new control, HEURFORCESPECIALOBJ, has been introduce to force alternative objective local search heuristics to run on a MIP, even when the automatic strategy has determined they should not be run.
• More choices for TUNERTARGET when tuning a MIP.
• New function, XPRSfeaturequery, to query which features are allowed by the current license.
• Quadratic constraints in binary variables can now be linearized when this appears beneficial.
• All Xpress-Nonlinear functionality is now included in the XPRS library file. It is no longer necessary to link against the XSLP library.

Xpress Mosel 4.8.0 Compiler library

• Long file names are no longer truncated when reporting error messages

Native interface

• LP/MIP matrix manipulation routines are now avaiable from the NI
• New service 'PROVIDER'

moseldoc

• New tag 'recfldval' for documeting record field values

mmnl 1.8.0

• New functions 'erf' and 'erfc'

mmxprs 2.14.0

• New procedure 'hasfeature' to check license features

mmsvg 1.2.0

• New versions of 'svgwaitclose' to change behavior on browser window closing in Workbench
• New style property 'SVG_ANIMATE'

Xpress Workbench 2.1

• Compiler errors are highlighted and can be clicked to jump to the source location
• Compiler looks for bim file dependencies in the same directory as the source files
• If a model raises an error while debugging, the debugger stops at the line where the error occurred
• More Mosel module symbols are autocompleted
• Insight sidebar is automatically opened for Insight projects only
• Improved error reporting when Mosel model crashes
• Improved size and position of Workbench window on low resolution displays
• Improved error reporting when Mosel graph cannot be reopened

Xpress Nonlinear 32.01.03

• Significantly improved performance on numerically challenging problems.
• Added support for the min/max functions both in Mosel and through API.
• Added support for the erf (standard error function) and its complement erfc to the API and Mosel.
• Work with best solutions: XSLP_FILTER bit 1 is now default. Checks now include the initial solution.
• New attribute XSLP_SOLSTATUS to indicate if a solution is available. This attribute complements XSLP_NLPSTATUS.
• New attribute XSLP_VALIDATIONSTATUS to check if the current solution is deemed feasible, set up by XSLPvalidate.
• New attribute XSLP_TOTALEVALUATIONERRORS to indicate the number of evaluation errors that occurred during a solve.
• New API function XSLPnlpoptimize to solve the problem using the existing optimization sense.
• New option for XSLP_HEURSTRATEGY to include all heuristics with no effort limits imposed.
• Mosel can now read and write solutions of nonlinear problems using 'writesol' and 'readsol'.
• All Xpress-Nonlinear functionality is now included in the XPRS library file. It is no longer necessary to link against the XSLP library.
• Deprecated functions in this release:

  XSLPloadivfs, XSLPaddivfs, XSLPchgivf, XSLPdelivf, XSLPgetivformula,
  XSLPloadxvs , XSLPaddxvs, XSLPchgxv, XSLPchgxvitem, XSLPdelxvs, XSLPgetxv,XSLPgetxvitemformula,
  XSLPloaddcs, XSLPadddcs, XSLPchgdc, XSLPdeldcs, XSLPgetdcformula, XSLPopt,
  XSLPsetcbmessageF, XSLPsetcbitervarF, XSLPsetcbcascadevarF

Xpress Kalis 12.6.1

• Implemented Mosel restrictions

Fixed in Release 8.4.0

_{Back to top}

Xpress Mosel 4.8.0

Compiler library

• An issue has been fixed in the handling of extended types in packages

XPRD

• Java: an issue has been fixed in the handling of connection string parameters

mmquad 1.2.9

• Objective modification now always reported to optimiser

mmssl 1.4.1

• An issue has been fixed in the 'hex' driver when used for reading

mmxml 2.2.3

• JSON reader: possible failure when loading a file containing only an empty string

mmxprs 2.14.0

• Using mmquad no longer prevents optimising linear objectives

Xpress Workbench 2.1

• Fixed issue where arrays of arrays could not be inspected in the debugger
• Fixed issue where cursor was sometimes drawn in the wrong place when editing source files
• Fixed issue where model output was truncated after 5000 lines
• Fixed issue where variables tree could not be resized
• Fixed issue where Mosel annotations were only autocompleted once
• Fixed long delays when saving files, running Mosel models, and publishing to Insight
• Fixed error when running Mosel models: "Couldn't reserve space for cygwin's heap"
• Fixed issue with copying a source file

BCL 4.8.13

• Fixed .Net issue with garbage collection of prob object while dependent objects are still in use
• Fixed .Net issue with garbage collector finalizing objects while native methods still need the resources they wrap

Fixed in Release 8.3.3

_{Back to top}

Xpress Mosel 4.6.1

Compiler Library

• An issue has been fixed in the handling of extended types in packages

XPRD

• Java: an issue has been fixed in the handling of connection string parameters

mmquad 1.2.9

• objective modification now always reported to optimiser

mmssl 1.4.1

• An issue has been fixed in the 'hex' driver when used for reading

mmxml 2.2.3

• JSON reader: possible failure when loading a file containing only an empty string

mmxprs 2.12.1

• Using mmquad no longer prevents optimising linear objectives

mmxnlp 31.01.12

• Fixed error when mmxnlp would crash if loaded without being licensed.

Examples

• Relocate IVE examples so they are visible to IVE's Complete Models wizard.

Xpress Workbench 2.0.2

• Fixed long delays when saving files, running Mosel models, and publishing to Insight
• Fixed error when running Mosel models: "Couldn't reserve space for cygwin's heap"
• Copying a source file not working

Fixed in Release 8.3.2

_{Back to top} Xpress-Nonlinear 31.01.12

• Fixed an issue in which XSLP_UNFINISHEDLIMIT was always used as value 1.

Fixed in Release 8.3.1

_{Back to top} Xpress-Optimizer 31.01.10

• Duplicate row eliminations should now be more robust against badly scaled rows.
• Fixed an issue with the loading of a basis file in compact format when super-basic variables are already present in the problem.
• Fixed a problem when turning crossover on for quadratic problems.
• Do not report the parallel crossover banner during MIP search.
• Fixed an uninitialized name bug in the Python interface.

Xpress-Nonlinear 31.01.11

• Fixed a potential problem with nonlinear eliminations in refinery type models.
• Improved numerical behavior for quadratic problems.

Xpress-Nonlinear 31.01.10

• Fixed a problem in which an infeasible converged solution was declared optimal.

Xpress-BCL 4.8.12

• Fixed .Net issue with garbage collector finalizing objects while native methods still need the resources they wrap

XPRL 2.8.7

• Remove some restrictions on number of active connections to license server.

New in Release 8.3

_{Back to top} Xpress Optimizer/NonLinear 31.01.09

• The Xpress Python interface now allows for creating and solving nonlinear optimization problems. The modeling capabilities that were introduced with the first Python interface in Xpress 8.0 are extended to create constraints with expressions of arbitrary complexity using nonlinear operators. The interface also allows for accessing the full power of the Xpress-Nonlinear API for querying and modifying nonlinear problems.

Xpress Mosel 4.6.0 Language

• New function 'setname(mpvar,string)'
• New function 'newmuid' to generate a unique identifier
• New annotation property 'strict'
• New syntax for 'with' (equivalent to a single iteration 'forall' loop)

Native interface

• Operator '@_' may receive now an entity with a reference count >1
• New function 'newmuid' to generate a unique identifier

Compiler Library

• New compiler flag '-we' to handle warnings as errors

mmjobs 2.14.0

• New procedure 'getdsoprop' to retrieve module information
• Support for interval timers (routines settimer, gettimer and canceltimer)

mmnl 1.6.3

• New functions 'fmin' and 'fmax'

mmrobust 1.4.0

• New function 'getact(robustctr)'

mmsheet 1.4.3

• xlsx/xls/csv: selecting an entire row for writing has the same effect as using the 'grow' option (same behavious as Excel)
• Excel driver: initialising a scalar with an empty cell now resets the variable (same behaviour as other drivers)

mmsvg 0.0.1

• New package for creating graphs in SVG format and displaying them in a web browser or within Workbench
• Graphing functionality includes circle, pie, polygon, polyline, xmltext objects and SVG styling for groups or individual objects
• This package supercedes the mmive module

mmxprs 2.12.0

• New procedure 'readsol' with an array to store the solution
• New function 'getname(nlctr)'

S3 0.0.3

• Added support for server-side encryption using Amazon-managed encryption keys (SSE-S3)

mosjvm 1.0.0

• New module allowing Mosel to instantiate a Java virtual machine (Windows/Linux only)

Xpress Workbench 2.0.0

• Xpress Workbench is the new integrated development environment for the Xpress Optimization Suite.
• Compile, run and debug Mosel models
• Deploy and remotely debug Xpress Insight apps.
• Syntax highlighting, autocompletion and code folding for Mosel and VDL source files and Xpress Insight companion files.
• Integrates with the Xpress tuner.
• Integrates with Tableau for FICO Server for Tableau workbook authoring

Xpress Kalis 12.6.0

• Removed kalis parameters which are not prefixed with "kalis_" (they were already deprecated)
• Added a model "scenesalloc" in the examples to show the impact of symmetry breaking

Fixed in Release 8.3

_{Back to top} Xpress Mosel 4.6.0 Compiler Library

• Non-empty annotation categories are now propagated in packages
• Annotation definitions are now always published properly in packages

mmsheet 1.4.3

• All drivers: an error is now reported when initialising a scalar with an unsufficient number of columns

Xpress NonLinear 31.01.09

• Includes all fixes applied since the initial Xpress 8.2 release with NonLinear 31.01.02 up to and including Xpress NonLinear 31.01.09. Please refer to the Xpress 8.2 patch notes for the specific fixes.

Xpress Kalis 12.6.0

• Fixed a bug in the subroutine "disjunctive"
• Other minor bug fixes.

BCL 4.8.11

• Fixed Java issue when addMIPSol is called with a null name

New in Release 8.2

_{Back to top} Xpress-Optimizer 31.01.02

• It is now possible to tune a set of problem instances with the console Optimizer.
  • A set of problem instances can be specified by listing them in a text file and passing this file to the tune command as "tune probset <set-filename>".
  • Tuning target will be the aggregate across the set of instances.
• Setting TUNERTHREADS=-1 will now automatically use all available logical cores for tuning.
• The tuner output log now includes a summary of the importance of each individual control setting from the best control set.
• Crossover after a Barrier solve is now multi-threaded. A new control, CROSSOVERTHREADS, has been introduced to set the maximum number of threads to use during crossover.
• A new function, XPRSgetlastbarsol, has been introduced, which can be used to retrieve the solution from the last Barrier solve, assuming it was successful. This can e.g. be used for retrieving the solution from Barrier in case the crossover phase timed out.
• Efficiency changes to the multi-threaded MIP code:
  • Reduced the overhead for small, easy MIPs.
  • Reduced the memory usage for very large MIPs, especially those that are significantly reduced during the initial preprocessing.

Xpress-Mosel 4.4.0 mosel

• Option '-sdir' now accepts a list of directories and may be stated several times
• Debugger:
  • new 'breaksub' command
  • the model causing the interruption is now automatically selected
  • new command 'lsattr' to list types attributes
  • command 'print' now supports all type attributes (e.g. getsize(text))

Language

• Loops (forall,repeat and while) can now be preceded by a label of the form 'string|identifier:'
• 'break' and 'next' accept now an identifier or string as parameter: it is interpreted as a label for the loop
• New constant INFINITY and functions 'isinf(real)', 'isfinite(real)'
• New function 'isdynamic'
• New option 'fctasproc': when it is used functions can be used as procedures (i.e. their return value is silently ignored)
• New procedure 'asproc' to call a function and ignore its return value
• User types (defining sets) can now be used to define array indices

Remote invocation

• New option 'dbgbrksub'
• New command 'lsattr'

Runtime Library

• Default compatility convention for modules and packages is changing:

        a1.b1.c1 is compatible with a2.b2.c2 if
        (a1=a2) and ((b1<b2) or ((b1=b2) and (c2>=c1)))

  Up to this release the rule was:

        (a1=a2) and (b1=b2) and (c2>=c1)

• New functions 'findtypeattr', 'getattr' and 'getnexttypeattr' for type attribute management

Native interface

• New functions 'finddsofct','realtostr','hmfind','findtypeattr','getattr'
• New service 'SVC_REQTYPS' to list type requirements

mmhttp 2.4.0

• Support for HEAD requests (function 'httphead')
• New function 'httppending' to get a list of requests waiting for a reply

mmjobs 2.12.0

• New function 'waitexpired'
• 'tmp:' can now be used as the working directory of a remote model

mmodbc 3.2.1

• upgrade to SQLite 3.17.0

mmsheet 1.4.2

• xlsx: handling of ranges consisting in all columns or all rows now similar to Excel

mmsystem 2.4.0

• constructor 'text(x)' can now be used with structured entities

s3 1.0.0

• New Mosel library for uploading/downloading objects from an Amazon S3 bucket

matlab 1.0.4

• Added support for UTF-8 strings

Xpress-Nonlinear 31.01.02

• Improved logic for finding initial points when none provided. New control XSLP_FINDIV indicating if initial values should automatically be determined
• Improved bound reduction in presolve through linear and quadratic coefficients. New control XSLP_LINQUADBR indicating if bound reduction should consider linear and quadratic coefficients as well as nonlinear expressions
• Support for variables with integer, semi-continuous or exploration type delta variables.
  • New delta types for nonlinear variables:
    • Integer delta: for variables that take values at integer multiples of a given step value
    • Semi-continuous delta: for variables that need to be changed at least by a given amount to have a measurable effect
    • Explore delta: for variables that are used in functions with zero partials at an unknown size
  • New API function XSLPchgdeltatype and Mosel function setdeltatype to mark variables as having a specific delta type
  • New control XSLP_GRIDHEURSELECT to indicate which heuristics to execute:
    • Enumeration: for small search spaces, evaluate all combinations
    • Cyclic: simple local search heuristics
    • Simulated annealing: simulated annealing enhanced local search heuristics
• Code generation tool for parallelizing user (black box) functions in Mosel. New Mosel function 'generateUFparallel' available in the mmxnlp package
• Extended capabilities for warm starting SLP solves using the LP barrier solver
  • Automatic fallback to the interior point solution found by barrier in case of crossover effort limits being hit
  • New control XSLP_BARSTARTOPS: allows fine tuning how barrier is applied in initial SLP iterations
  • New control XSLP_BARCROSSOVERSTART: specifies when to activate crossover; aimed at very large problem instances
  • New control XSLP_BARSTALLINGLIMIT: automatic numerical stalling fallback for barrier starts
  • New control XSLP_BARSTALLINGOBJLIMIT: automatic progress stalling fallback for barrier starts
  • New control XSLP_BARSTALLINGTOL: automatic progress stalling fallback tolerance for barrier starts

Fixed in Release 8.2

_{Back to top}

Xpress-Mosel 4.4.0

Compiler Library

• An issue has been resolved in the handling of 'forall' loop constants
• Negative constants can now be used for indices in inline initialisation
• A constant set/list can now be initialised from a record field
• An issue has been resolved in the handling of '#line' markers in combination with empty statements in 'then' or 'else' constructs

mmjobs 2.12.0

• Windows: an event is now always available if 'wait(t)' returns before the time limit

mmodbc 3.2.1

• NULL data result now properly handled by 'SQLreadstring'
• An issue has been fixed in SQLexecute when it is used to export a set

mmsystem 2.4.0

• An issue has been fixed in the handling of comparisons of time/date/datetime when one of the operands is null
• 'findfiles' now ignores non-existent directories in filters
• 'findfiles' no longer includes a leading directory separator in file names of its result set
• 'findfiles' no longer fails to retrieve subdirectories on some file systems (Linux)

matlab 1.0.4

• Fixed non initialized error code when reading an empty set

BCL 4.8.10

• Fixed a possible memory leak when reaching memory exhaustion
• Improved tracking of allocated memory for .Net

New in Release 8.1

_{Back to top}

Xpress-Optimizer 30.01.04

• A new performance Tuner is available through the Optimizer console, the API and the Mosel modelling language. The Tuner automates the search for good control settings for solving a given problem, or class of problems, more efficiently.
  • Allows for tuning of all problem types supported by the Xpress Optimizer and Xpress Nonlinear.
  • Tuning can be performed against permuted versions of the original instance in order to ensure tuned results are more robust against small problem changes.
  • A new console command, TUNE, is available for starting a tuning session on a loaded problem.
  • A new API function, XPRStune, has been introduced for tuning a problem through the API.
  • New controls have been introduced for configuring the new Tuner:

    TUNERHISTORY     Whether to re-use previous results when restarting the Tuner.
    TUNERMAXTIME     Time limit for the entire tuning session.
    TUNERMETHOD      Selects which built-in method the Tuner should use when searching through possible control combinations.
    TUNERMODE        Can be used to specify that a Tuner session should be run before a problem is solved.
    TUNEROUTPUT      Controls the amount of logging output from the Tuner.
    TUNERPERMUTE     Number of permutations of the original problem to include in a Tuner session, in addition to the original problem.
    TUNERTARGET      The Tuner goal, such as improve solve time, best bound or best solution.
    TUNERTHREADS     Number of threads used by the Tuner
    TUNERMETHODFILE  The location of a file describing which control settings to tune against.
    TUNEROUTPUTPATH  A directory where Tuner results will be written to.
    TUNERSESSIONNAME String identifier for the Tuner session. Results will be recorded to a folder with this name in the TUNEROUTPUTPATH location.

• Dual Simplex now includes Sifting, which can speed up the solve of LPs with many more columns than rows. A new control, SIFTING, has been introduced to select when to run the Sifting algorithm.
• It is now possible to warm-start a Barrier solve by providing a primal solution, a dual solution or both. A starting solution can be loaded through the API with XPRSloadlpsol, or from a file using XPRSreadslxsol. Setting the control BARSTART=-1 will cause Barrier to use a pre-loaded solution for warm-starting, if one exists.
• A new local search heuristic is available for MIPs, based on interior point solutions. It is most useful for finding a first feasible solution. A new bit 6 has been introduced in HEURSEARCHROOTSELECT and HEURSEARCHTREESELECT to enable or disable this heuristic.
• Improved presolving for MIPs with a large number of precedence constraints. A new control, PREIMPLICATIONS, has been introduced to control this feature.
• A new control, MIPRAMPUP, has been introduced to control the ramp-up phase of parallel MIP.
• Aggregated Mixed Integer Rounding cuts have been improved for network-type problems.
• Flow path cuts are now disabled by default. To enable them, clear bit 11 of the CUTSELECT or the TREECUTSELECT controls.
• The Python API is now compatible with Python 2.7.
• The Python API now supports all Optimizer callback functions.
• The control CPUPLATFORM for selecting vectorization support now has two additional settings:

  -1: Automatically select the highest deterministic support [SSE2, AVX].
  -2: Automatically select the highest support [SSE2, AVX, AVX2].

  Selecting AVX2 can result in a different solve path than Generic, SSE2 or AVX.
• A new API function, XPRS_ge_setarchconsistency has been introduced. It can be used to ensure solver behavior that is consistent across systems with different levels of vectorization support [SSE2, AVX or AVX2].
• A new control, CROSSOVERITERLIMT, has been introduced to set the iteration limit for crossover.
• A new control, CROSSOVEROPS, has been introduced to allow for tuning of crossover.
• Added new control CROSSOVERITERLIMT to set iteration limit for crossover

Xpress-Mosel 4.2.0 mosel

• New option '-sdm sdm' to the the maximum depth of a stack dump. This can also be set with the environment variable MOSEL_SDMAX
• New execution option '-cov' and command 'cover[age]' to perform code coverage of models -
• New option '-sdir dir' to select the location of profiler/debugger source and report files
• Debugger: new command 'finish' (continue up to end of subroutine)

Language

• New procedures 'fwrite[ln][_]' taking a stream number (integer) as the first argument. These procedures make it possible to write to an error stream
• Assertion error messages are now send to the model error stream
• New statement 'return' to quit the current subroutine
• New functions 'setmatherr', 'NAN' and 'isnan'
• New control parameter 'mathctrl' to disable failure on math error

Runtime Library

• Improved efficiency of memory management
• Improved performance on writing text files in DOS format
• Operation R:=S with R being a range and S a set of integers containing one element is now supported
• Notation "\uxxxx" can now be used to represent Unicode characters in string constants
• After a runtime error Mosel now dumps its call stack. The maximum depth of this dump is defined using function 'XPRMsetsdmax' (default is 0)
• New functions 'XPRMsetsdmax' and 'XPRMgetsdmax'
• Function 'getmodprop(PROP_NAME)' now returns the initial model name. To get the internal unique name use property PROP_UNAME

Native interface

• New service 'SVC_DSOSTRE' to implement a dso stream

Compiler Library

• Verification of the syntax of annotations has been improved
• Procedure 'setparam' is now more restrictive regarding type conversion

moseldoc

• Support for documentation of annotations (doc.annot.*)

Remote invocation

• New command 'covres' to retrieve code coverage information (model must have been run in profiling mode)
• New parameter 'sdmax' to set the maximum stack dump size
• Parameter 'dbgctrl': new value 'F' to continue execution up to the end of the current subroutine
• Command 'dbgflndx' now includes an additional array ('name') to report the function names. If used with no parameter it returns the line indices for all available routines. By default the result set is unsorted: option 'N' sorts it according to routine names and option 'L' uses the line indices as the sorting criteria
• Eval: new function 'getmodprop' to retrieve model information

xprmsrv

• New option '-tc' to display the server configuration
• Configuration can now be updated while the server is running (Windows: with '-service reload' command; Unix: USR1 signal)
• New configuration variable 'CONFDIR': this is a directory path where are located additional configuration files (read after the main file)
• New context specific configuration variables RUN_BEFORE and RUN_AFTER
• New notation '[context]+': append definitions only if "context" exists
• New notation '[context]=': replace definitions "context"
• XPRMSRV_ACCESS: definition of a network from a host name (e.g. "myhost/24")
• XPRMSRV_ACCESS: new special identifier "SELF" (server hostname)

mmhttp 2.2.0

• New version of 'httpreply'/'httpreplycode' with an additional parameter to include supplementary headers to the response
• New procedure 'httpcancel' to cancel an asynchronous request
• New parameters 'http_maxcontime' and 'http_maxreqtime' to set maximum duration of requests
• Support for 'gzip' content encoding in results for httpget/put/post/del
• New function 'httpgetheader' to extract the header of a result file

mmjobs 2.10.1

• Propagate sdmax setting to remote instances
• New procedure 'getmodprop' to retrieve model information

mmnl 1.6.2

• Support for control parameter 'mathctrl'

mmodbc 3.2.0

• Extented syntax now supports 3-digits parameter indices (e.g. '?101')
• Both extended and standard syntax can now be used in the same query
• The 'mmsqlite' driver now includes the extension functions from: http://www.sqlite.org/contrib/download/extension-functions.c

mmquad 1.2.8

• LP format: append '/2' to quadratic obective
• Support for control parameter 'mathctrl'

mmsheet 1.4.1

• Upgrade to libxl 3.7.1

mmssl 1.4.0

• Support for SSL operations with time limit (for https)

mmsystem 2.2.0

• New function 'formattext'

mmxml 2.2.2

• New versions of 'getnode' & 'getnodes' accepting a 'text' parameter

mmxprs 2.10.1

• New optimisation option XPRS_TUNE to enable the tuner

Xpress-Nonlinear 30.01.04

• The automatic differentiation tool now supports parallel calculations. New control XSLP_CALCTHREADS can be used to manually set the number of threads used.
• The nonlinear eliminations in presolve have been made more efficient.
• The nonlinear presolver may now shrink the problem size. Use XSLP_PRESOLVESTATE to determine if the problem is in a presolved state. To prevent SLP from shrinking the problem size, set the XSLP_PRESOLVELEVEL control to smaller than full.
• XSLPgetslpsol always return the solution to the original problem. XSLPgetslpsol now only return values for columns and rows present in the original problem.
• New attributes XSLP_ORIGINALCOLS and XSLP_ORIGINALTOWS can be used to return the original number of model rows and columns in the problem.

Xpress-Kalis 12.4.0

• Add parameter KALIS_SCHEDULE_ENABLE_SHAVING to control whether or not activate shaving step when scheduling
• Fixed a bug in the tree search disjunction display in Xpress-IVE.
• Fixed a rare bug preventing Xpress-Kalis from finding the optimal solution to certain scheduling problems.

Fixed in Release 8.1

_{Back to top}

Xpress-Mosel 4.1

Compiler Library

• An issue has been resolved in the processing of multi-lines annotations
• An issue has been resolved in the processing of annotations when option 'explterm' is being used
• An issue has been resolved in the handling of loop local variables of the form 'v=value' when 'value' is not an integer

Runtime Library

• A potential memory corruption has been fixed in the 'findident' function when it is used by an NI routine during a debugging session
• The 'null:' IO driver no longer enforces binary mode (this was causing issues with XML output)
• Statement A+=B where both A and B are ranges and A is empty no longer results in a runtime error
• Option EP_STRIP no longer ignored (exportprob)

mmhttp 2.2.0

• 'urlencode' now handles UTF-8 characters properly

mmjobs 2.10.1

• An issue in the comparison to 'nullevent' has been fixed
• Event objects are now initialised with 'nullevent'

mmodbc 3.2.0

• A potential memory corruption has been fixed in the handling of empty results when reading sets or lists

mmsystem 2.2.0

• A potential 'bus error' has been fixed in 'getsize(text)' (Sparc only)

mmxml 2.2.2

• JSON reader: notation '\uxxxx' can now process unicode values >255
• The default encoding of an XML document is now UTF-8

zlib 1.4.1

• A potential memory corruption has been fixed in the zip file driver

BCL 4.8.9

• Fixed the format of the eventual constant term in the objective when exporting a problem to LP file

New in Release 8.0.4

_{Back to top} Xpress-Optimizer 29.01.10

• The parallel MIP code has been completely rewritten to improve performance and scalability. The MIP API and solver interaction through callbacks remains mostly unaffected.
  • The worker tasks have been decoupled from the number of running threads. The solution path followed by the MIP solver now depends only on the worker task limit and not on the number of running solver threads.
  • A new control, MAXMIPTASKS, has been introduced to manually limit the number of MIP worker tasks. The number of running threads is still given by MIPTHREADS (which is derived from THREADS on automatic setting). By setting MAXMIPTASKS to a fixed number, the MIP solver will always return the same deterministic solution independent of the number of cores on the host machine, assuming that the LP threading controls have also been set to a fixed number. To guarantee a deterministic outcome for any number of cores, the following controls should be set: MAXMIPTASKS to a positive value. BARTHREADS to a positive value FORCEPARALLELDUAL=1 CONCURRENTTHREADS to a positive value, or do not run concurrent.
  • A new control MIPTERMINATIONMETHOD determines how to complete worker tasks in case of an early termination (time limit, node limit, etc).
  • Heuristics can now be run in parallel with cutting in deterministic mode. Previously, heuristics would only be run in parallel after cutting.
• It is now possible to create a basic solution from a not necessarily basic LP solution vector.
  • A new API function, XPRScrossoverlpsol, has been introduced to run the crossover algorithm on a user solution loaded through memory or from a file.
  • A new API function, XPRSloadlpsol, to load a solution vector from memory into the Optimizer. It will be set up as a solution without a basis, to the current LP problem in memory.
  • A new control, PREPROTECTDUAL, that can be used to specify whether the presolving of a problem with a loaded LP solution should avoid any reductions that could introduce dual infeasibilities.
• Introduced code support for AVX2 in the Barrier solver.
  • Set CPUPLATFORM=3 to enable AVX2 code support (when supported by the host CPU).
• Improved performance and numerical stability of crossover.
• A new control, BARORDERTHREADS, has been introduced to set the number of concurrent threads for the sparse matrix ordering in the barrier algorithm.
• New presolve reductions, strengthenings and reformulations for convex quadratic and conic problems.
  • A new control, PRECONEDECOMP, has been introduced to specify whether large cones should be decomposed when solving an MISOCP problem using an outer approximation method.
• Improved implementation of zero-half cutting for MIPs.
• The LP solution refiner can now run before postsolve to address any scaling infeasibilities. New bit option for XPRS_REFINEOPS has been added, and is enabled by default.
• The LP solution refiner now allows target values larger then the the feasibility and optimality tolerance, to be used on the post-solved problem.
• The effect of setting controls during the MIP search is now deterministic (if the MIP is solved in deterministic mode).
• A new control, HEURSEARCHROOTCUTFREQ, which can be used to specify how frequently root local search heuristics should be run between rounds of cuts.
• A new zero-objective local search heuristic to help find a first feasible solution for MIPs. Enabled by turning on bit 5 of the HEURSEARCHROOTSELECT and HEURSEARCHTREESELECT controls.
• A new control, ADDMIPSOLHEURISTIC, to control the local search heuristic that will be applied to infeasible or partial solutions loaded with XPRSaddmipsol.
• It is now possible to get rows and columns sorted as part of presolve. This could e.g. be used to ensure that a problem solves the same way regardless of the order in which variables and constraints have been declared.
  • A new control, PRESORT, has been introduced to specify whether to sort rows, columns or the global entity list.
  • New controls, PREPERMUTE and PREPERMUTESEED, have been introduce to allow rows, columns or the global entity list to be permuted randomly.
• The control MPSFORMAT now defaults to free format with a value of 1.
• The control CSTYLE no longer has any effect and will be removed from future releases.
• The control HEURSEARCHROOTSELECT new defaults to 53 which enables two additional local search heuristics during the root node processing.
• New Python interface for Xpress-Optimizer (requires Python 3.4 or newer and NumPy 1.1 or newer).
• The Java interface requires a minimum of Java 6 (internal version: 1.6.0)
• The Visual Basic interface is only supported via VB.NET

Xpress-Mosel 4.0.3 See Upgrading to Mosel 5 for details on upgrading Mosel models from 3.X to 4.0.

Mosel now represents all its internal strings in UTF-8 and supports character encoding conversions.

Remote Mosel instances can now be controled via remote queries in addition to usual XPRD/mmjobs queries. A query takes the form of a special file (to be open for reading) that is interpreted as a command: the data file returned by the instance is the result of the query. Supported commands:

  eval      evaluate an expression
  info      properties of Mosel, model/package/module
  lsloc     retrieve a list of local symbols
  lslib     list of available modules and packages
  profres   result of a profiling session
  dbglndx   mapping of line+file names in a model
  dbgbrkp   breakpoint management
  dbgstat   execution status
  dbgstlev  stack management
  dbgflndx  location of a subroutine

Language

• New procedures 'publish' and 'unpublish' to control visibility of private and local symbols at runtime
• New functions _() and _c() for message translation
• New procedures write_ and writeln_ for message translation
• Annotations mc.msgdom and mc.msgid for message translation
• New procedure 'setioerr' to raise an IO error from the Mosel code

Mosel

• New option '-l' to select the language
• Debugger: new command 'lslocal' to display a list of local symbols

xprmsrv

• The standard protocol can now be disabled by setting the tcp port to -1 (in this case the server starts only if the ssh protocol is enabled)
• New server parameter SSH_CIPHERS (and command line option '-sc') to select which ciphers are accepted for SSH sessions

XPRNLS

• The new 'xprnls' library implements various character encoding routines as well as message catalog management (for message translation)
• The 'xprnls' command tool is a character encoding converter (i.e. it makes it possible to convert text files from an encoding to another) and a message catalog processor

XPRD

• Java: file manager routines now intercept all exceptions instead of only IOExceptions
• New function 'XPRDinstid' (C) and 'XPRDMosel.getId' (Java) to retrieve the ID of an instance (=node number)

BinDrv

• Java version: string handling functions accept now an additional parameter for selecting the character encoding (default: UTF-8)

Java interface

• The Java interface requires a minimum of Java 6 (internal version: 1.6.0)
• New method to retrieve local identifiers (XPRMModel.localIdentifiers)
• When a PrintStream is used as a text output stream via the 'mmjava:' driver and no encoding is specified, data is sent as text strings to the 'print' method (this enables Java encoding conversion).

Visual Basic interface

• The Visual Basic interface is no longer supported by VB6, only via VBA and VB.NET
• VBA: some functions that take or return pointers have been changed to use Variant rather than Long (in 32-bit) or LongPtr (in 64-bit)
• VBA: The XPRM_IO_CB function can now be used to create callback-based I/O handlers for any text output, not just as an argument to XPRMsetdefstream

Compiler Library

• All routines working with strings now expect UTF-8 strings
• Source file encoding may be specified using the '!@encoding' annotation to be put at the beginning of the file. For instance: !@encoding:ISO-8859-15
• New compiler option '-x' to generate a POT file from a model (message translation)
• Verification of the syntax of annotations has been improved

Runtime Library

• All routines working with strings now expect UTF-8 strings
• New 'enc:' filename prefix to select encoding. By default text files are expected to be in UTF-8 and detect UTF-16 and UTF-32.
• 'initialisations' data files can specify an encoding using the special comment '!@encoding' to be put at the beginning of the file. For instance: !@encoding:CP1252
• New function 'XPRMdbg_getnextlocal' to enumerate local symbols during a debugging session
• New function 'XPRMdbg_getlndx' to retrieve all lines indices at once
• If restriction 'NoExec' is active, modules that are not located in read-only directories are now ignored
• Mosel can now be installed under bin32/lib32/dso32 (32bit build) and bin64/lib64/dso64 (64bit build). This makes it possible to have both 32bit and 64bit distributions under the same directory tree
• Operation R:=S with R being a range and S a set of integers containing one element is now supported

Native Interface (NI)

• Deprecated IO routine 'IOCTRL_ERROR' no longer supported
• IO driver routine 'IOCTRL_OPEN' now receives an additional parameter (encoding of the stream)

mmetc 1.8.5

• Switch to xprnls for message translation

mmhttp 2.0.0

• Consecutive requests to a given server are now processed using a single connection
• New control parameters 'http_expire' and 'http_maxconn' to manage the pool of connections
• Switch to UTF-8 encoding

mmjobs 2.10.0

• Deleting the file "shmem:*" has the effect of deleting all memory files handled by 'shmem'
• 'rmt:' driver: r/w error messages from the remote host are now displayed
• New parameter 'defaultnode': this is the node number used by 'rmt:' when no node reference is given - switch to UTF-8 encoding

mmnl 1.6.1

• Switch to xprnls for message translation

mmoci 1.6.0

• Communication with the database in UTF-8
• Option 'debug' now disabled if model is not compiled in debug mode

mmodbc 3.0.0

• Support for ANSI (default on Posix) and UNICODE (default for Windows) ODBC interfaces
• Interface can be selected with the 'enc:' filename prefix
• Option 'debug' now disabled if model is not compiled in debug mode
• New procedure SQLindices to retrieve the indices of a table
• SQLite driver: support for ':memory:' and empty file name databases

mmquad 1.2.7

• Switch to xprnls for message translation

mmrobust 1.2.1

• Switch to xprnls for message translation

mmsheet 1.4.0

• Switch to UTF-8 encoding
• Driver 'csv': strings starting with '0' or spaces are no longer implicitly interpreted as numbers
• Empty records are now skipped when reading a list of records

mmssl 1.2.0

• Switch to UTF-8 encoding

mmsystem 2.0.0

• All string operations now performed in UTF-8
• New value -1 for 'qtype' (quoting mode) disables quoting
• 'zip' and 'tar' routines can select the encoding used for file names (in the archive) using the 'enc:' prefix on the archive name
• IMCI: new functions 'gettime'/'settime', 'getdate'/'setdate', 'getdatetime'/'setdatetime'

mmxml 2.2.0

• XML documents are now encoded/decoded according to the specified encoding
• JSON documents are now properly handled as UTF-8
• Procedure 'getnodes' and 'getnode' no longer fail when applied to node 0 on an empty document
• New function 'getsize(xmldoc)' to get the number of nodes of a document
• Control parameter 'xml_keeputf' has been removed (no longer necessary)

mmxprs 2.10.0

• Switch to UTF-8 encoding

zlib 1.4.0

• Support for UTF-8 in file names

deploy 2.0.0

• Switch to UTF-8 encoding
• Support for program parameters containing non-ascii symbols

r 1.0.12

• Added support for restricted R on FAC

Non-Linear 29.01.10

• New default convergence mechanism for improved solution quality
  • new control XSLP_VALIDATIONTARGET_K to specify target first order optimality accuracy.
  • new control XSLP_VALIDATIONTARGET_R to specify target relative validation accuracy.
  • new values for XSLP_CONVERGENCEOPS to allow disabling / enabling the target convergence options.
  • new default value for XSLP_CONVERGENCEOPS to reflect the use of the target convergence checks.
  • the traditional SLP convergence controls now default to -1, their values are dynamically adjusted during the run. U ser set values are respected as normal and are not modified. The controls that now default to -1 are XSLP_CTOL, XSLP_ATOL_A, XSLP_ATOL_R, XSLP_MTOL_A, XSLP_MTOL_R, XSLP_ITOL_A, XSLP_ITOL_R, XSLP_STOL_A, XSLP_STOL_R, XSLP_MVTOL, XSLP_XTOL_A, XSLP_XTOL_R, XSLP_OTOL_A, XSLP_OTOL_R, XSLP_VTOL_A, XSLP_VTOL_R, XSLP_EVTOL_A, XSLP_EVTOL_R, XSLP_ECFTOL_A, XSLP_ECFTOL_R, XSLP_WTOL_A and XSLP_WTOL_R.
• The mixed integer nonlinear solver MISLP has been reworked
  • much improved general performance.
  • the default MINLP solver now runs in parallel mode for the tree search.
  • greatly increased heuristics capability for the MINLP solver.
• Probing algorithm based on the bound reduction algorithm to further tighten variable bounds; it works on several levels (which can be set automatically or by the user) for applying probing to different classes of variables.
• The VB interface is no longer supported, except in VB.NET. User functions written in VB6 or VBA are still supported, provided that they do not need to call the XSLP API.
• Upgraded Knitro to version 10.0.

BCL 4.8.8

• Added C/C++/Java/.NET functions to iterate over constraints and constraint terms
• Added/extended XPRBterm and XPRMqterm classes to Java and .Net to allow inspection of iterated constraint terms
• Changed getIIS Java/.Net method to retrieve the first IIS by default instead of the IIS approximation
• Added error code return to C++ functions that can fail on out of memory
• The VB interface is no longer supported, except in VB.NET
• The interface to Java requires a minimum of Java 6 (internal version: 1.6.0)

IVE 1.24.12

• Supports Mosel UTF-8 encoding

XAD 1.2.10

• Supports Mosel UTF-8 encoding

Fixed in Release 8.0.4

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• Debugger: 'getsize' now reports the expected value when applied to strings produced from external types

Compiler Library

• Redeclaration of a constant scalar no longer leads to a corrupted bim file
• An issue has been resolved in the processing of multi-lines annotations

mmodbc 3.0.0

• 64bit platforms: a potential memory corruption has been fixed

mmsheet 1.4.0

• Excel driver: a possible crash on Windows 8.1 64Bit and newer has been fixed
• xls/xlsx/csv drivers: conversion from boolean to string now valid

mmsystem 2.0.0

• Parsetext now updates 'endparse' when used with a parse context
• mmsystem.text driver now fails when trying to write to an unitialised object

mmxprs 2.10.0

• Optimiser status 'MIP_LP_NOT_OPTIMAL' now interpreted as 'unfinished'
• 'defsecurevecs' no longer ignores set of rows if a set of variables is used
• A potential memory corruption has been fixed in getloaded{mpvars|linctrs}
• 'savemipsol' no longer reports an error when used on a presolved problem

BCL 4.8.8

• Fixed issue with 'getIIS' when used to access the IIS approximation
• Fixed 'printcut' to print using problem pointer
• Fixed error message in 'printctr'/'printidxset'
• Fixed extra cut printing in 'xbgetcuts'

IVE 1.24.12

• Fixed Excel issue, where model deployed to VBA would occasionally have incorrect working directory
• Fixed issue where file might fail to laod if start and end aligned with memory boundary

Known issues in Release 8.0

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