CallbackAPI

Add an afterobjective callback.

More details about afterobjective callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, afterobjective.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbafterobjective()

Add a bariteration callback.

More details about bariteration callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, bariteration.

p_action

Defines a return value controlling barrier:

• <0: continue with the next iteration;
• =0: let barrier decide (use default stopping criteria);
• 1: barrier stops with status not defined;
• 2: barrier stops with optimal status;
• 3: barrier stops with dual infeasible status;
• 4: barrier stops wih primal infeasible status.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbbariteration()

Add a barlog callback.

More details about barlog callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, barlog.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbbarlog()

Add a beforeobjective callback.

More details about beforeobjective callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, beforeobjective.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbbeforeobjective()

Add a changebranchobject callback.

More details about changebranchobject callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

branch

p_newbranch

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbchangebranchobject()

Add a checktime callback.

More details about checktime callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, checktime.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbchecktime()

Add a computerestart callback.

More details about computerestart callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, computerestart.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbcomputerestart()

Add a cutlog callback.

More details about cutlog callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, cutlog.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbcutlog()

Add a cutround callback.

More details about cutround callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, cutround.

ifxpresscuts

An integer set to 1 if the Optimizer will apply a round of cuts after this callback. 0 otherwise.

p_action

An integer return value that specifies the action the Optimizer should take:

• -1: Continue unchanged. The default action.
• 0: No further rounds of cuts should be applied on this node.
• 1: The Optimizer should apply one more round of cutting, regardless of the value of ifxpresscuts
• 2: The Optimizer should process any changes applied during this callback and fire the callback again, but skip any Optimizer cutting.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbcutround()

Add a gapnotify callback.

More details about gapnotify callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The current problem.

p_relgapnotifytarget

The value the MIPRELGAPNOTIFY control will be set to after this callback. May be modified within the callback in order to set a new notification target.

p_absgapnotifytarget

The value the MIPABSGAPNOTIFY control will be set to after this callback. May be modified within the callback in order to set a new notification target.

p_absgapnotifyobjtarget

The value the MIPABSGAPNOTIFYOBJ control will be set to after this callback. May be modified within the callback in order to set a new notification target.

p_absgapnotifyboundtarget

The value the MIPABSGAPNOTIFYBOUND control will be set to after this callback. May be modified within the callback in order to set a new notification target.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbgapnotify()

Add an infnode callback.

More details about infnode callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, infnode.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbinfnode()

Add an intsol callback.

More details about intsol callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, intsol.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbintsol()

Add a lplog callback.

More details about lplog callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, lplog.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcblplog()

Add a message callback.

More details about message callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

msg

A null terminated character array (string) containing the message, which may simply be a new line. The total number of bytes (including NUL terminator) will not exceed XPRS_MAXMESSAGELENGTH. If a message needs to be truncated to meet this limit, the last four bytes in msg are set to "...\0".

msglen

The length of the message string, excluding the null terminator.

msgtype

Indicates the type of output message:

• 1: information messages;
• 2: (not used);
• 3: warning messages;
• 4: error messages.

A negative value indicates that the Optimizer is about to finish and the buffers should be flushed at this time if the output is being redirected to a file.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbmessage()

Add a miplog callback.

More details about miplog callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, miplog.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbmiplog()

Add a mipthread callback.

More details about mipthread callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

threadprob

The new problem for the MIP thread

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbmipthread()

Add a mipthreaddestroy callback.

More details about mipthreaddestroy callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbmipthreaddestroy()

Add a msjobend callback.

More details about msjobend callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

jobdata

Job specific user-defined object, as specified by the multistart job creating API functions.

jobdesc

The description of the problem as specified by the multistart job creating API functions.

p_status

User return status variable:

0 - use the default evaluation of the finished job

1 - disregard the result and continue

2 - stop the multistart search

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbmsjobend()

Add a msjobstart callback.

More details about msjobstart callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

jobdata

Job specific user-defined object, as specified by the multistart job creating API functions.

jobdesc

The description of the problem as specified by the multistart job creating API functions.

p_status

User return status variable:

0 - normal return, solve the job,

1 - disregard this job and continue,

2 - Stop multistart.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbmsjobstart()

Add a mswinner callback.

More details about mswinner callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

jobdata

Job specific user-defined object, as specified by the multistart job creating API functions.

jobdesc

The description of the problem as specified by the multistart job creating API functions.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbmswinner()

Add a newnode callback.

More details about newnode callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, newnode.

parentnode

Unique identifier for the parent of the new node.

node

Unique identifier assigned to the new node.

branch

The sequence number of the new node amongst the child nodes of parentnode. For regular branches on a MIP entity this will be either 0 or 1.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbnewnode()

Add a nlpcoefevalerror callback.

More details about nlpcoefevalerror callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

col

The column position of the coefficient.

row

The row position of the coefficient.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbnlpcoefevalerror()

Add a nodecutoff callback.

More details about nodecutoff callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, nodecutoff.

node

The node id of the node that is cut off. This id cannot be queried from the CURRENTNODE attribute as for other callbacks since this callback is not invoked in the context of the node being cutoff.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbnodecutoff()

Add a nodelpsolved callback.

More details about nodelpsolved callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, nodelpsolved.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbnodelpsolved()

Add an optnode callback.

More details about optnode callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, optnode.

p_infeasible

The feasibility status. If set to a nonzero value by the user, the current node will be declared infeasible.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcboptnode()

Add a preintsol callback.

More details about preintsol callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, preintsol.

soltype

The type of MIP solution that has been found:

• 0: The continuous relaxation solution to the current node of the tree search, which has been found to be integer feasible.
• 1: A MIP solution found by a heuristic.
• 2: A MIP solution provided by the user.

p_reject

Set this to 1 if the solution should be rejected. When soltype is zero, this will also drop the node problem.

p_cutoff

The new cutoff value that the Optimizer will use if the solution is accepted.

If p_cutoff is assigned a value, the new value will be used instead. The cutoff value will not be updated if the solution is rejected.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbpreintsol()

Add a prenode callback.

More details about prenode callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, prenode.

p_infeasible

The feasibility status. If set to a nonzero value by the user, the current node will be declared infeasible by the Optimizer.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbprenode()

Add a presolve callback.

More details about presolve callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbpresolve()

Add a slpcascadeend callback.

More details about slpcascadeend callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpcascadeend()

Add a slpcascadestart callback.

More details about slpcascadestart callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpcascadestart()

Add a slpcascadevar callback.

More details about slpcascadevar callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

col

The number of the column which has been cascaded.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpcascadevar()

Add a slpcascadevarfail callback.

More details about slpcascadevarfail callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

col

The number of the column which has been cascaded.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpcascadevarfail()

Add a slpconstruct callback.

More details about slpconstruct callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpconstruct()

Add a slpdrcol callback.

More details about slpdrcol callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

col

The index of the column for which the determining columns is checked.

detcol

The index of the determining column for the column that is being updated.

detval

The value of the determining column in the current SLP iteration.

p_value

Used to return the new value for column col, should it need to be updated, in which case the callback must return a positive result to indicate that this value should be used.

lb

The original lower bound of column col. The callback provides this value as a reference, should the bound be updated or changed during the solution process.

ub

The original upper bound of column col. The callback provides this value as a reference, should the bound be updated or changed during the solution process.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpdrcol()

Add a slpintsol callback.

More details about slpintsol callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpintsol()

Add a slpiterend callback.

More details about slpiterend callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpiterend()

Add a slpiterstart callback.

More details about slpiterstart callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpiterstart()

Add a slpitervar callback.

More details about slpitervar callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

col

The number of the column which has been tested for convergence.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslpitervar()

Add a slppreupdatelinearization callback.

More details about slppreupdatelinearization callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function.

ifrepeat

Indicates the call number, starting at 1.

If returned nonzero, another call to the callback will be scheduled. If returned zero, a final call with ifrepeat set to -1 will be made.

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbslppreupdatelinearization()

Add an usersolnotify callback.

More details about usersolnotify callbacks can be found in the documentation of the corresponding C callback. The callback function takes the following arguments:

cbprob

The problem passed to the callback function, usersolnotify.

solname

The string name assigned to the solution when it was loaded into the Optimizer using XPRSaddmipsol.

status

One of the following status values:

• 1: Solution is feasible. (XPRS_USERSOLSTATUS_ACCEPTED_FEASIBLE)
• 2: Solution is feasible after reoptimizing with fixed MIP entities. (XPRS_USERSOLSTATUS_ACCEPTED_OPTIMIZED)
• 3: A local search heuristic was applied and a feasible solution discovered. (XPRS_USERSOLSTATUS_SEARCHED_SOL)
• 4: A local search heuristic was applied but a feasible solution was not found. (XPRS_USERSOLSTATUS_SEARCHED_NOSOL)
• 5: Solution is infeasible and a local search could not be applied. (XPRS_USERSOLSTATUS_REJECTED_INFEAS_NOSEARCH)
• 6: Solution is partial and a local search could not be applied. (XPRS_USERSOLSTATUS_REJECTED_PARTIAL_NOSEARCH)
• 7: Failed to reoptimize the problem with MIP entities fixed to the provided solution. Likely because a time or iteration limit was reached. (XPRS_USERSOLSTATUS_REJECTED_FAILED_OPTIMIZE)
• 8: Solution is dropped. This can happen if the MIP problem is changed or solved to completion before the solution could be processed. (XPRS_USERSOLSTATUS_DROPPED)
• 9: The solution is worse than the current MIP cutoff value. (XPRS_USERSOLSTATUS_REJECTED_CUTOFF)

Parameters

callback	Callback function.
prio	Callback priority.

Returns

A handle that can be used to remove the callback later.

See also

C documentation of XPRSaddcbusersolnotify()

Remove an afterobjective callback.

Parameters

callback

The callback to be removed (previously returned by addAfterObjectiveCallback).

Remove a bariteration callback.

Parameters

callback

The callback to be removed (previously returned by addBarIterationCallback).

Remove a barlog callback.

Parameters

callback

The callback to be removed (previously returned by addBarlogCallback).

Remove a beforeobjective callback.

Parameters

callback

The callback to be removed (previously returned by addBeforeObjectiveCallback).

Remove a changebranchobject callback.

Parameters

callback

The callback to be removed (previously returned by addChangeBranchObjectCallback).

Remove a checktime callback.

Parameters

callback

The callback to be removed (previously returned by addCheckTimeCallback).

Remove a computerestart callback.

Parameters

callback

The callback to be removed (previously returned by addComputeRestartCallback).

Remove a cutlog callback.

Parameters

callback

The callback to be removed (previously returned by addCutlogCallback).

Remove a cutround callback.

Parameters

callback

The callback to be removed (previously returned by addCutRoundCallback).

Remove a gapnotify callback.

Parameters

callback

The callback to be removed (previously returned by addGapNotifyCallback).

Remove an infnode callback.

Parameters

callback

The callback to be removed (previously returned by addInfnodeCallback).

Remove an intsol callback.

Parameters

callback

The callback to be removed (previously returned by addIntsolCallback).

Remove a lplog callback.

Parameters

callback

The callback to be removed (previously returned by addLplogCallback).

Remove a message callback.

Parameters

callback

The callback to be removed (previously returned by addMessageCallback).

Remove a miplog callback.

Parameters

callback

The callback to be removed (previously returned by addMiplogCallback).

Remove a mipthread callback.

Parameters

callback

The callback to be removed (previously returned by addMipThreadCallback).

Remove a mipthreaddestroy callback.

Parameters

callback

The callback to be removed (previously returned by addMipThreadDestroyCallback).

Remove a msjobend callback.

Parameters

callback

The callback to be removed (previously returned by addMsJobEndCallback).

Remove a msjobstart callback.

Parameters

callback

The callback to be removed (previously returned by addMsJobStartCallback).

Remove a mswinner callback.

Parameters

callback

The callback to be removed (previously returned by addMsWinnerCallback).

Remove a newnode callback.

Parameters

callback

The callback to be removed (previously returned by addNewnodeCallback).

Remove a nlpcoefevalerror callback.

Parameters

callback

The callback to be removed (previously returned by addNlpCoefEvalErrorCallback).

Remove a nodecutoff callback.

Parameters

callback

The callback to be removed (previously returned by addNodecutoffCallback).

Remove a nodelpsolved callback.

Parameters

callback

The callback to be removed (previously returned by addNodeLPSolvedCallback).

Remove an optnode callback.

Parameters

callback

The callback to be removed (previously returned by addOptnodeCallback).

Remove a preintsol callback.

Parameters

callback

The callback to be removed (previously returned by addPreIntsolCallback).

Remove a prenode callback.

Parameters

callback

The callback to be removed (previously returned by addPrenodeCallback).

Remove a presolve callback.

Parameters

callback

The callback to be removed (previously returned by addPresolveCallback).

Remove a slpcascadeend callback.

Parameters

callback

The callback to be removed (previously returned by addSlpCascadeEndCallback).

Remove a slpcascadestart callback.

Parameters

callback

The callback to be removed (previously returned by addSlpCascadeStartCallback).

Remove a slpcascadevar callback.

Parameters

callback

The callback to be removed (previously returned by addSlpCascadeVarCallback).

Remove a slpcascadevarfail callback.

Parameters

callback

The callback to be removed (previously returned by addSlpCascadeVarFailCallback).

Remove a slpconstruct callback.

Parameters

callback

The callback to be removed (previously returned by addSlpConstructCallback).

Remove a slpdrcol callback.

Parameters

callback

The callback to be removed (previously returned by addSlpDrColCallback).

Remove a slpintsol callback.

Parameters

callback

The callback to be removed (previously returned by addSlpIntSolCallback).

Remove a slpiterend callback.

Parameters

callback

The callback to be removed (previously returned by addSlpIterEndCallback).

Remove a slpiterstart callback.

Parameters

callback

The callback to be removed (previously returned by addSlpIterStartCallback).

Remove a slpitervar callback.

Parameters

callback

The callback to be removed (previously returned by addSlpIterVarCallback).

Remove a slppreupdatelinearization callback.

Parameters

callback

The callback to be removed (previously returned by addSlpPreUpdateLinearizationCallback).

Remove an usersolnotify callback.

Parameters

callback

The callback to be removed (previously returned by addUserSolNotifyCallback).