Detailed Description
methods and datastructures for conflict analysis
This file implements a conflict analysis method like the one used in modern SAT solvers like zchaff. The algorithm works as follows:
Given is a set of bound changes that are not allowed being applied simultaneously, because they render the current node infeasible (e.g. because a single constraint is infeasible in the these bounds, or because the LP relaxation is infeasible). The goal is to deduce a clause on variables – a conflict clause – representing the "reason" for this conflict, i.e., the branching decisions or the deductions (applied e.g. in domain propagation) that lead to the conflict. This clause can then be added to the constraint set to help cutting off similar parts of the branch and bound tree, that would lead to the same conflict. A conflict clause can also be generated, if the conflict was detected by a locally valid constraint. In this case, the resulting conflict clause is also locally valid in the same depth as the conflict detecting constraint. If all involved variables are binary, a linear (set covering) constraint can be generated, otherwise a bound disjunction constraint is generated. Details are given in
Tobias Achterberg, Conflict Analysis in Mixed Integer Programming
Discrete Optimization, 4, 4-20 (2007)
See also How to use conflict analysis. Here is an outline of the algorithm:
- Put all the given bound changes to a priority queue, which is ordered, such that the bound change that was applied last due to branching or deduction is at the top of the queue. The variables in the queue are always active problem variables. Because binary variables are preferred over general integer variables, integer variables are put on the priority queue prior to the binary variables. Create an empty conflict set.
- Remove the top bound change b from the priority queue.
- Perform the following case distinction:
- If the remaining queue is non-empty, and bound change b' (the one that is now on the top of the queue) was applied at the same depth level as b, and if b was a deduction with known inference reason, and if the inference constraint's valid depth is smaller or equal to the conflict detecting constraint's valid depth:
- Resolve bound change b by asking the constraint that inferred the bound change to put all the bound changes on the priority queue, that lead to the deduction of b. Note that these bound changes have at most the same inference depth level as b, and were deduced earlier than b.
- Otherwise, the bound change b was a branching decision or a deduction with missing inference reason, or the inference constraint's validity is more local than the one of the conflict detecting constraint.
- If a the bound changed corresponds to a binary variable, add it or its negation to the conflict set, depending on which of them is currently fixed to FALSE (i.e., the conflict set consists of literals that cannot be FALSE altogether at the same time).
- Otherwise put the bound change into the conflict set. Note that if the bound change was a branching, all deduced bound changes remaining in the priority queue have smaller inference depth level than b, since deductions are always applied after the branching decisions. However, there is the possibility, that b was a deduction, where the inference reason was not given or the inference constraint was too local. With this lack of information, we must treat the deduced bound change like a branching, and there may exist other deduced bound changes of the same inference depth level in the priority queue.
- If the remaining queue is non-empty, and bound change b' (the one that is now on the top of the queue) was applied at the same depth level as b, and if b was a deduction with known inference reason, and if the inference constraint's valid depth is smaller or equal to the conflict detecting constraint's valid depth:
- If priority queue is non-empty, goto step 2.
- The conflict set represents the conflict clause saying that at least one of the conflict variables must take a different value. The conflict set is then passed to the conflict handlers, that may create a corresponding constraint (e.g. a logicor constraint or bound disjunction constraint) out of these conflict variables and add it to the problem.
If all deduced bound changes come with (global) inference information, depending on the conflict analyzing strategy, the resulting conflict set has the following property:
- 1-FirstUIP: In the depth level where the conflict was found, at most one variable assigned at that level is member of the conflict set. This conflict variable is the first unique implication point of its depth level (FUIP).
- All-FirstUIP: For each depth level, at most one variable assigned at that level is member of the conflict set. This conflict variable is the first unique implication point of its depth level (FUIP).
The user has to do the following to get the conflict analysis running in its current implementation:
- A constraint handler or propagator supporting the conflict analysis must implement the CONSRESPROP/PROPRESPROP call, that processes a bound change inference b and puts all the reason bounds leading to the application of b with calls to SCIPaddConflictBound() on the conflict queue (algorithm step 3.(a)).
- If the current bounds lead to a deduction of a bound change (e.g. in domain propagation), a constraint handler should call SCIPinferVarLbCons() or SCIPinferVarUbCons(), thus providing the constraint that inferred the bound change. A propagator should call SCIPinferVarLbProp() or SCIPinferVarUbProp() instead, thus providing a pointer to itself.
- If (in the current bounds) an infeasibility is detected, the constraint handler or propagator should
- call SCIPinitConflictAnalysis() to initialize the conflict queue,
- call SCIPaddConflictBound() for each bound that lead to the conflict,
- call SCIPanalyzeConflictCons() or SCIPanalyzeConflict() to analyze the conflict and add an appropriate conflict constraint.
Definition in file conflict_graphanalysis.c.
#include "lpi/lpi.h"
#include "scip/conflict_graphanalysis.h"
#include "scip/conflict_dualproofanalysis.h"
#include "scip/clock.h"
#include "scip/conflict.h"
#include "scip/cons.h"
#include "scip/cons_linear.h"
#include "scip/cuts.h"
#include "scip/history.h"
#include "scip/lp.h"
#include "scip/presolve.h"
#include "scip/prob.h"
#include "scip/prop.h"
#include "scip/pub_conflict.h"
#include "scip/pub_cons.h"
#include "scip/pub_lp.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_misc_sort.h"
#include "scip/pub_paramset.h"
#include "scip/pub_prop.h"
#include "scip/pub_tree.h"
#include "scip/pub_var.h"
#include "scip/scip_conflict.h"
#include "scip/scip_cons.h"
#include "scip/scip_mem.h"
#include "scip/scip_sol.h"
#include "scip/scip_var.h"
#include "scip/set.h"
#include "scip/sol.h"
#include "scip/struct_conflict.h"
#include "scip/struct_lp.h"
#include "scip/struct_prob.h"
#include "scip/struct_set.h"
#include "scip/struct_stat.h"
#include "scip/struct_tree.h"
#include "scip/struct_var.h"
#include "scip/tree.h"
#include "scip/var.h"
#include "scip/visual.h"
#include <string.h>
#include <strings.h>
Go to the source code of this file.
Function Documentation
◆ conflictsetEnsureBdchginfosMem()
|
static |
Conflict sets resizes the arrays of the conflict set to be able to store at least num bound change entries
- Parameters
-
conflictset conflict set blkmem block memory of transformed problem set global SCIP settings num minimal number of slots in arrays
Definition at line 378 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, SCIP_ConflictSet::bdchginfossize, BMSreallocBlockMemoryArray, NULL, SCIP_ConflictSet::relaxedbds, SCIP_ALLOC, SCIP_OKAY, SCIPsetCalcMemGrowSize(), and SCIP_ConflictSet::sortvals.
Referenced by conflictsetAddBound(), and conflictsetAddBounds().
◆ conflictsetAddBound()
|
static |
adds a bound change to a conflict set
- Parameters
-
conflictset conflict set blkmem block memory of transformed problem set global SCIP settings bdchginfo bound change to add to the conflict set relaxedbd relaxed bound
Definition at line 405 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, conflictsetEnsureBdchginfosMem(), SCIP_ConflictSet::hasrelaxonlyvar, MAX, MIN, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsTighter(), SCIPsortedvecDelPosIntPtrReal(), SCIPsortedvecInsertIntPtrReal(), SCIPvarGetIndex(), SCIPvarIsRelaxationOnly(), SCIP_ConflictSet::sortvals, and TRUE.
Referenced by conflictAddConflictBound(), and conflictsetAddBounds().
◆ conflictsetCalcConflictDepth()
|
static |
calculates the conflict and the repropagation depths of the conflict set
- Parameters
-
conflictset conflict set
Definition at line 478 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, SCIP_ConflictSet::conflictdepth, SCIP_ConflictSet::insertdepth, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::repropdepth, SCIPbdchginfoGetDepth(), and SCIP_ConflictSet::validdepth.
Referenced by conflictInsertConflictset().
◆ conflictsetCalcInsertDepth()
|
static |
identifies the depth, at which the conflict set should be added:
- if the branching rule operates on variables only, and if all branching variables up to a certain depth level are member of the conflict, the conflict constraint can only be violated in the subtree of the node at that depth, because in all other nodes, at least one of these branching variables violates its conflicting bound, such that the conflict constraint is feasible
- if there is at least one branching variable in a node, we assume, that this branching was performed on variables, and that the siblings of this node are disjunct w.r.t. the branching variables' fixings
- we have to add the conflict set at least in the valid depth of the initial conflict set, so we start searching at the first branching after this depth level, i.e. validdepth+1
- Parameters
-
conflictset conflict set set global SCIP settings tree branch and bound tree
Definition at line 522 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, BMSclearMemoryArray, SCIP_ConflictSet::insertdepth, MIN, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_Tree::pathlen, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPbdchginfoGetDepth(), SCIPsetAllocBufferArray, SCIPsetFreeBufferArray, SCIPtreeGetCurrentDepth(), TRUE, and SCIP_ConflictSet::validdepth.
Referenced by conflictAddConflictset().
◆ conflictsetIsRedundant()
|
static |
checks whether the first conflict set is redundant to the second one
- Parameters
-
conflictset1 first conflict conflict set conflictset2 second conflict conflict set
Definition at line 569 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, FALSE, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_BOUNDTYPE_LOWER, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsTighter(), SCIPdebugPrintf, SCIPvarGetName(), SCIP_ConflictSet::sortvals, and SCIP_ConflictSet::validdepth.
Referenced by conflictInsertConflictset().
◆ checkRedundancy()
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static |
check conflict set for redundancy, other conflicts in the same conflict analysis could have led to global reductions an made this conflict set redundant
- Parameters
-
set global SCIP settings conflictset conflict set
Definition at line 633 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, bound, FALSE, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPsetIsFeasGE(), SCIPsetIsFeasLE(), SCIPsetIsGE(), SCIPsetIsIntegral(), SCIPsetIsLE(), SCIPvarGetLbGlobal(), SCIPvarGetProbindex(), SCIPvarGetType(), SCIPvarGetUbGlobal(), and TRUE.
Referenced by detectImpliedBounds().
◆ detectImpliedBounds()
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static |
find global fixings which can be derived from the new conflict set
- Parameters
-
set global SCIP settings prob transformed problem after presolve stat dynamic SCIP statistics tree tree data blkmem block memory origprob original problem reopt reoptimization data lp LP data conflictset conflict set to add to the tree nbdchgs number of global deducted bound changes due to the conflict set nredvars number of redundant and removed variables from conflict set redundant did we found a global reduction on a conflict set variable, which makes this conflict redundant
Definition at line 698 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, BMSclearMemoryArray, bound, checkRedundancy(), FALSE, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_Bool, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_Longint, SCIP_OKAY, SCIP_Real, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPboundtypeOpposite(), SCIPnodeCutoff(), SCIPprobGetName(), SCIPprobIsTransformed(), SCIPsetAllocBufferArray, SCIPsetAllocCleanBufferArray, SCIPsetDebugMsg, SCIPsetDebugMsgPrint, SCIPsetFreeBufferArray, SCIPsetFreeCleanBufferArray, SCIPsetIsEQ(), SCIPsetIsFeasEQ(), SCIPsetIsFeasGT(), SCIPsetIsFeasLT(), SCIPsetIsGE(), SCIPsetIsIntegral(), SCIPsetIsLE(), SCIPsetIsZero(), SCIPshrinkDisjunctiveVarSet(), SCIPsortLongPtrRealRealBool(), SCIPtreeGetRootNode(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetNCliques(), SCIPvarGetNVlbs(), SCIPvarGetNVubs(), SCIPvarGetProbindex(), SCIPvarGetUbGlobal(), SCIPvarIsBinary(), SCIPvarIsIntegral(), SCIP_ConflictSet::sortvals, and TRUE.
Referenced by conflictAddConflictCons().
◆ conflictsetClear()
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static |
clears the given conflict set
- Parameters
-
conflictset conflict set
Definition at line 971 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::conflictdepth, SCIP_ConflictSet::conflicttype, FALSE, SCIP_ConflictSet::hasrelaxonlyvar, SCIP_ConflictSet::insertdepth, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::repropagate, SCIP_ConflictSet::repropdepth, SCIP_CONFTYPE_UNKNOWN, TRUE, SCIP_ConflictSet::usescutoffbound, and SCIP_ConflictSet::validdepth.
Referenced by conflictClear(), and SCIPconflictsetCreate().
◆ SCIPconflictsetCreate()
SCIP_RETCODE SCIPconflictsetCreate | ( | SCIP_CONFLICTSET ** | conflictset, |
BMS_BLKMEM * | blkmem | ||
) |
creates an empty conflict set
- Parameters
-
conflictset pointer to store the conflict set blkmem block memory of transformed problem
Definition at line 989 of file conflict_graphanalysis.c.
References BMSallocBlockMemory, conflictsetClear(), NULL, SCIP_ALLOC, and SCIP_OKAY.
Referenced by SCIPconflictCreate().
◆ conflictsetCopy()
|
static |
creates a copy of the given conflict set, allocating an additional amount of memory
- Parameters
-
targetconflictset pointer to store the conflict set blkmem block memory of transformed problem sourceconflictset source conflict set nadditionalelems number of additional elements to allocate memory for
Definition at line 1009 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, BMSallocBlockMemory, BMSallocBlockMemoryArray, BMScopyMemoryArray, SCIP_ConflictSet::conflictdepth, SCIP_ConflictSet::conflicttype, SCIP_ConflictSet::hasrelaxonlyvar, SCIP_ConflictSet::insertdepth, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_ConflictSet::repropdepth, SCIP_ALLOC, SCIP_OKAY, SCIP_ConflictSet::sortvals, SCIP_ConflictSet::usescutoffbound, and SCIP_ConflictSet::validdepth.
Referenced by conflictAddConflictset().
◆ SCIPconflictsetFree()
void SCIPconflictsetFree | ( | SCIP_CONFLICTSET ** | conflictset, |
BMS_BLKMEM * | blkmem | ||
) |
frees a conflict set
- Parameters
-
conflictset pointer to the conflict set blkmem block memory of transformed problem
Definition at line 1045 of file conflict_graphanalysis.c.
References BMSfreeBlockMemory, BMSfreeBlockMemoryArrayNull, and NULL.
Referenced by conflictAddConflictset(), conflictInsertConflictset(), SCIPconflictFlushConss(), and SCIPconflictFree().
◆ conflictsetCalcScore()
|
static |
calculates the score of the conflict set
the score is weighted sum of number of bound changes, repropagation depth, and valid depth
- Parameters
-
conflictset conflict set set global SCIP settings
Definition at line 1064 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::repropdepth, and SCIP_ConflictSet::validdepth.
Referenced by conflictInsertConflictset().
◆ SCIP_DECL_PARAMCHGD()
|
static |
method to call, when the priority of a conflict handler was changed
Definition at line 1095 of file conflict_graphanalysis.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIPparamGetData(), SCIPparamGetInt(), and SCIPsetConflicthdlrPriority().
◆ SCIPconflicthdlrCopyInclude()
SCIP_RETCODE SCIPconflicthdlrCopyInclude | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_SET * | set | ||
) |
copies the given conflict handler to a new scip
- Parameters
-
conflicthdlr conflict handler set SCIP_SET of SCIP to copy to
Definition at line 1109 of file conflict_graphanalysis.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIPconflicthdlrGetName(), and SCIPsetDebugMsg.
Referenced by SCIPsetCopyPlugins().
◆ doConflicthdlrCreate()
|
static |
internal method for creating a conflict handler
- Parameters
-
conflicthdlr pointer to conflict handler data structure set global SCIP settings messagehdlr message handler blkmem block memory for parameter settings name name of conflict handler desc description of conflict handler priority priority of the conflict handler conflicthdlrdata conflict handler data
Definition at line 1129 of file conflict_graphanalysis.c.
References BMSallocMemory, BMSclearMemory, BMSduplicateMemoryArray, FALSE, NULL, paramname, SCIP_ALLOC, SCIP_CALL, SCIP_CLOCKTYPE_DEFAULT, SCIP_MAXSTRLEN, SCIP_OKAY, SCIPclockCreate(), SCIPsetAddIntParam(), SCIPsnprintf(), and TRUE.
Referenced by SCIPconflicthdlrCreate().
◆ SCIPconflicthdlrCreate()
SCIP_RETCODE SCIPconflicthdlrCreate | ( | SCIP_CONFLICTHDLR ** | conflicthdlr, |
SCIP_SET * | set, | ||
SCIP_MESSAGEHDLR * | messagehdlr, | ||
BMS_BLKMEM * | blkmem, | ||
const char * | name, | ||
const char * | desc, | ||
int | priority, | ||
SCIP_DECL_CONFLICTCOPY((*conflictcopy)) | , | ||
SCIP_DECL_CONFLICTFREE((*conflictfree)) | , | ||
SCIP_DECL_CONFLICTINIT((*conflictinit)) | , | ||
SCIP_DECL_CONFLICTEXIT((*conflictexit)) | , | ||
SCIP_DECL_CONFLICTINITSOL((*conflictinitsol)) | , | ||
SCIP_DECL_CONFLICTEXITSOL((*conflictexitsol)) | , | ||
SCIP_DECL_CONFLICTEXEC((*conflictexec)) | , | ||
SCIP_CONFLICTHDLRDATA * | conflicthdlrdata | ||
) |
creates a conflict handler
- Parameters
-
conflicthdlr pointer to conflict handler data structure set global SCIP settings messagehdlr message handler blkmem block memory for parameter settings name name of conflict handler desc description of conflict handler priority priority of the conflict handler conflicthdlrdata conflict handler data
Definition at line 1183 of file conflict_graphanalysis.c.
References doConflicthdlrCreate(), NULL, SCIP_CALL_FINALLY, SCIP_OKAY, and SCIPconflicthdlrFree().
Referenced by SCIPincludeConflicthdlr(), and SCIPincludeConflicthdlrBasic().
◆ SCIPconflicthdlrFree()
SCIP_RETCODE SCIPconflicthdlrFree | ( | SCIP_CONFLICTHDLR ** | conflicthdlr, |
SCIP_SET * | set | ||
) |
calls destructor and frees memory of conflict handler
- Parameters
-
conflicthdlr pointer to conflict handler data structure set global SCIP settings
Definition at line 1214 of file conflict_graphanalysis.c.
References BMSfreeMemory, BMSfreeMemoryArrayNull, NULL, SCIP_CALL, SCIP_OKAY, and SCIPclockFree().
Referenced by SCIPconflicthdlrCreate().
◆ SCIPconflicthdlrInit()
SCIP_RETCODE SCIPconflicthdlrInit | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_SET * | set | ||
) |
calls initialization method of conflict handler
- Parameters
-
conflicthdlr conflict handler set global SCIP settings
Definition at line 1242 of file conflict_graphanalysis.c.
References SCIP_Conflicthdlr::conflicttime, SCIP_Conflicthdlr::initialized, SCIP_Conflicthdlr::name, NULL, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPclockReset(), SCIPclockStart(), SCIPclockStop(), SCIPerrorMessage, SCIP_Conflicthdlr::setuptime, and TRUE.
◆ SCIPconflicthdlrExit()
SCIP_RETCODE SCIPconflicthdlrExit | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_SET * | set | ||
) |
calls exit method of conflict handler
- Parameters
-
conflicthdlr conflict handler set global SCIP settings
Definition at line 1279 of file conflict_graphanalysis.c.
References FALSE, SCIP_Conflicthdlr::initialized, SCIP_Conflicthdlr::name, NULL, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), SCIPerrorMessage, and SCIP_Conflicthdlr::setuptime.
Referenced by SCIPsetInitPlugins().
◆ SCIPconflicthdlrInitsol()
SCIP_RETCODE SCIPconflicthdlrInitsol | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_SET * | set | ||
) |
informs conflict handler that the branch and bound process is being started
- Parameters
-
conflicthdlr conflict handler set global SCIP settings
Definition at line 1310 of file conflict_graphanalysis.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), and SCIP_Conflicthdlr::setuptime.
Referenced by SCIPsetExitprePlugins().
◆ SCIPconflicthdlrExitsol()
SCIP_RETCODE SCIPconflicthdlrExitsol | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_SET * | set | ||
) |
informs conflict handler that the branch and bound process data is being freed
- Parameters
-
conflicthdlr conflict handler set global SCIP settings
Definition at line 1334 of file conflict_graphanalysis.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), and SCIP_Conflicthdlr::setuptime.
Referenced by SCIPsetInitsolPlugins().
◆ SCIPconflicthdlrExec()
SCIP_RETCODE SCIPconflicthdlrExec | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_SET * | set, | ||
SCIP_NODE * | node, | ||
SCIP_NODE * | validnode, | ||
SCIP_BDCHGINFO ** | bdchginfos, | ||
SCIP_Real * | relaxedbds, | ||
int | nbdchginfos, | ||
SCIP_CONFTYPE | conftype, | ||
SCIP_Bool | usescutoffbound, | ||
SCIP_Bool | resolved, | ||
SCIP_RESULT * | result | ||
) |
calls execution method of conflict handler
- Parameters
-
conflicthdlr conflict handler set global SCIP settings node node to add conflict constraint to validnode node at which the constraint is valid bdchginfos bound change resembling the conflict set relaxedbds array with relaxed bounds which are efficient to create a valid conflict nbdchginfos number of bound changes in the conflict set conftype type of the conflict usescutoffbound depends the conflict on the cutoff bound? resolved was the conflict set already used to create a constraint? result pointer to store the result of the callback method
Definition at line 1358 of file conflict_graphanalysis.c.
References SCIP_Conflicthdlr::conflicttime, SCIP_Conflicthdlr::name, NULL, SCIP_CALL, SCIP_CONSADDED, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_INVALIDRESULT, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), SCIPerrorMessage, and SCIPnodeGetDepth().
Referenced by conflictAddConflictCons().
◆ SCIPconflicthdlrSetCopy()
void SCIPconflicthdlrSetCopy | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_DECL_CONFLICTCOPY((*conflictcopy)) | |||
) |
set copy method of conflict handler
- Parameters
-
conflicthdlr conflict handler
Definition at line 1426 of file conflict_graphanalysis.c.
References NULL.
Referenced by SCIPsetConflicthdlrCopy().
◆ SCIPconflicthdlrSetFree()
void SCIPconflicthdlrSetFree | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_DECL_CONFLICTFREE((*conflictfree)) | |||
) |
set destructor of conflict handler
- Parameters
-
conflicthdlr conflict handler
Definition at line 1437 of file conflict_graphanalysis.c.
References NULL.
Referenced by SCIPsetConflicthdlrFree().
◆ SCIPconflicthdlrSetInit()
void SCIPconflicthdlrSetInit | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_DECL_CONFLICTINIT((*conflictinit)) | |||
) |
set initialization method of conflict handler
- Parameters
-
conflicthdlr conflict handler
Definition at line 1449 of file conflict_graphanalysis.c.
References NULL.
Referenced by SCIPsetConflicthdlrInit().
◆ SCIPconflicthdlrSetExit()
void SCIPconflicthdlrSetExit | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_DECL_CONFLICTEXIT((*conflictexit)) | |||
) |
set deinitialization method of conflict handler
- Parameters
-
conflicthdlr conflict handler
Definition at line 1460 of file conflict_graphanalysis.c.
References NULL.
Referenced by SCIPsetConflicthdlrExit().
◆ SCIPconflicthdlrSetInitsol()
void SCIPconflicthdlrSetInitsol | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_DECL_CONFLICTINITSOL((*conflictinitsol)) | |||
) |
set solving process initialization method of conflict handler
- Parameters
-
conflicthdlr conflict handler
Definition at line 1471 of file conflict_graphanalysis.c.
References NULL.
Referenced by SCIPsetConflicthdlrInitsol().
◆ SCIPconflicthdlrSetExitsol()
void SCIPconflicthdlrSetExitsol | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_DECL_CONFLICTEXITSOL((*conflictexitsol)) | |||
) |
set solving process deinitialization method of conflict handler
- Parameters
-
conflicthdlr conflict handler
Definition at line 1482 of file conflict_graphanalysis.c.
References NULL.
Referenced by SCIPsetConflicthdlrExitsol().
◆ SCIPconflicthdlrSetPriority()
void SCIPconflicthdlrSetPriority | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_SET * | set, | ||
int | priority | ||
) |
sets priority of conflict handler
- Parameters
-
conflicthdlr conflict handler set global SCIP settings priority new priority of the conflict handler
Definition at line 1523 of file conflict_graphanalysis.c.
References FALSE, NULL, and SCIP_Conflicthdlr::priority.
Referenced by SCIPsetConflicthdlrPriority().
◆ SCIPconflicthdlrEnableOrDisableClocks()
void SCIPconflicthdlrEnableOrDisableClocks | ( | SCIP_CONFLICTHDLR * | conflicthdlr, |
SCIP_Bool | enable | ||
) |
enables or disables all clocks of conflicthdlr
, depending on the value of the flag
- Parameters
-
conflicthdlr the conflict handler for which all clocks should be enabled or disabled enable should the clocks of the conflict handler be enabled?
Definition at line 1547 of file conflict_graphanalysis.c.
References SCIP_Conflicthdlr::conflicttime, NULL, SCIPclockEnableOrDisable(), and SCIP_Conflicthdlr::setuptime.
Referenced by SCIP_DECL_PARAMCHGD().
◆ SCIPconflictApplicable()
return TRUE if conflict analysis is applicable; In case the function return FALSE there is no need to initialize the conflict analysis since it will not be applied
- Parameters
-
set global SCIP settings
Definition at line 1581 of file conflict_graphanalysis.c.
Referenced by SCIPconflictAnalyze(), and SCIPisConflictAnalysisApplicable().
◆ conflictEnsureTmpbdchginfosMem()
|
static |
resizes the array of the temporary bound change informations to be able to store at least num bound change entries
- Parameters
-
conflict conflict analysis data set global SCIP settings num minimal number of slots in arrays
Definition at line 1598 of file conflict_graphanalysis.c.
References BMSreallocMemoryArray, NULL, SCIP_ALLOC, SCIP_OKAY, SCIPsetCalcMemGrowSize(), SCIP_Conflict::tmpbdchginfos, and SCIP_Conflict::tmpbdchginfossize.
Referenced by conflictCreateTmpBdchginfo().
◆ conflictCreateTmpBdchginfo()
SCIP_RETCODE conflictCreateTmpBdchginfo | ( | SCIP_CONFLICT * | conflict, |
BMS_BLKMEM * | blkmem, | ||
SCIP_SET * | set, | ||
SCIP_VAR * | var, | ||
SCIP_BOUNDTYPE | boundtype, | ||
SCIP_Real | oldbound, | ||
SCIP_Real | newbound, | ||
SCIP_BDCHGINFO ** | bdchginfo | ||
) |
creates a temporary bound change information object that is destroyed after the conflict sets are flushed
- Parameters
-
conflict conflict analysis data blkmem block memory set global SCIP settings var active variable that changed the bounds boundtype type of bound for var: lower or upper bound oldbound old value for bound newbound new value for bound bdchginfo pointer to store bound change information
Definition at line 1621 of file conflict_graphanalysis.c.
References conflictEnsureTmpbdchginfosMem(), SCIP_Conflict::ntmpbdchginfos, NULL, SCIP_CALL, SCIP_OKAY, SCIPbdchginfoCreate(), and SCIP_Conflict::tmpbdchginfos.
Referenced by conflictCreateReconvergenceConss(), and SCIPconflictAnalyzeRemainingBdchgs().
◆ conflictFreeTmpBdchginfos()
|
static |
frees all temporarily created bound change information data
- Parameters
-
conflict conflict analysis data blkmem block memory
Definition at line 1645 of file conflict_graphanalysis.c.
References SCIP_Conflict::ntmpbdchginfos, NULL, SCIPbdchginfoFree(), and SCIP_Conflict::tmpbdchginfos.
Referenced by SCIPconflictFlushConss().
◆ incVSIDS()
|
static |
increases the conflict score of the variable in the given direction
- Parameters
-
var problem variable blkmem block memory set global SCIP settings stat dynamic problem statistics boundtype type of bound for which the score should be increased value value of the bound weight weight of this VSIDS updates
Definition at line 1661 of file conflict_graphanalysis.c.
References SCIP_Stat::glbhistory, SCIP_Stat::glbhistorycrun, NULL, SCIP_BOUNDTYPE_LOWER, SCIP_BRANCHDIR_DOWNWARDS, SCIP_BRANCHDIR_UPWARDS, SCIP_CALL, SCIP_OKAY, SCIPhistoryIncVSIDS(), SCIPsetIsZero(), SCIPvarIncVSIDS(), and SCIP_Stat::vsidsweight.
Referenced by conflictAddBound(), SCIPconflictAnalyzeRemainingBdchgs(), and updateStatistics().
◆ updateStatistics()
|
static |
update conflict statistics
- Parameters
-
conflict conflict analysis data blkmem block memory set global SCIP settings stat dynamic problem statistics conflictset conflict set to add to the tree insertdepth depth level at which the conflict set should be added
Definition at line 1692 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, bound, SCIP_Stat::glbhistory, SCIP_Stat::glbhistorycrun, incVSIDS(), SCIP_Conflict::nappliedglbconss, SCIP_Conflict::nappliedglbliterals, SCIP_Conflict::nappliedlocconss, SCIP_Conflict::nappliedlocliterals, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_BOUNDTYPE_LOWER, SCIP_BRANCHDIR_DOWNWARDS, SCIP_BRANCHDIR_UPWARDS, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPbdchginfoGetBoundtype(), SCIPhistoryIncNActiveConflicts(), SCIPvarIncNActiveConflicts(), and SCIP_BdChgInfo::var.
Referenced by conflictAddConflictCons().
◆ conflictAddConflictCons()
|
static |
adds the given conflict set as conflict constraint to the problem
- Parameters
-
conflict conflict analysis data blkmem block memory set global SCIP settings stat dynamic problem statistics transprob transformed problem after presolve origprob original problem tree branch and bound tree reopt reoptimization data structure lp current LP data branchcand branching candidate storage eventqueue event queue cliquetable clique table data structure conflictset conflict set to add to the tree insertdepth depth level at which the conflict set should be added success pointer to store whether the addition was successful
Definition at line 1743 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, bound, SCIP_BdChgInfo::boundtype, SCIP_ConflictSet::conflictdepth, SCIP_ConflictSet::conflicttype, detectImpliedBounds(), SCIP_Conflict::dIBclock, SCIP_Lp::diving, FALSE, h, SCIP_ConflictSet::hasrelaxonlyvar, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_Tree::path, SCIP_ConflictSet::relaxedbds, SCIP_Tree::root, SCIP_Bool, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_CONFTYPE_UNKNOWN, SCIP_CONSADDED, SCIP_OKAY, SCIP_Real, SCIPboundtypeOpposite(), SCIPclockStart(), SCIPclockStop(), SCIPconflicthdlrExec(), SCIPconflicthdlrGetName(), SCIPconflicthdlrGetPriority(), SCIPdebugCheckConflict, SCIPnodeAddBoundchg(), SCIPsetDebugMsg, SCIPsetIsIntegral(), SCIPsetSortConflicthdlrs(), SCIPtreeGetCurrentDepth(), SCIPtreeGetFocusDepth(), SCIPvarGetName(), SCIPvarIsIntegral(), SCIP_Lp::strongbranching, TRUE, updateStatistics(), SCIP_ConflictSet::usescutoffbound, SCIP_ConflictSet::validdepth, and SCIP_BdChgInfo::var.
Referenced by SCIPconflictFlushConss().
◆ conflictCalcMaxsize()
calculates the maximal size of conflict sets to be used
- Parameters
-
set global SCIP settings prob problem data
Definition at line 1896 of file conflict_graphanalysis.c.
References MAX, SCIP_Prob::ncontvars, NULL, and SCIP_Prob::nvars.
Referenced by SCIPconflictAnalyze(), SCIPconflictAnalyzeRemainingBdchgs(), and SCIPconflictFlushConss().
◆ SCIPconflictFlushConss()
SCIP_RETCODE SCIPconflictFlushConss | ( | SCIP_CONFLICT * | conflict, |
BMS_BLKMEM * | blkmem, | ||
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_PROB * | transprob, | ||
SCIP_PROB * | origprob, | ||
SCIP_TREE * | tree, | ||
SCIP_REOPT * | reopt, | ||
SCIP_LP * | lp, | ||
SCIP_BRANCHCAND * | branchcand, | ||
SCIP_EVENTQUEUE * | eventqueue, | ||
SCIP_CLIQUETABLE * | cliquetable | ||
) |
adds the collected conflict constraints to the corresponding nodes; the best set->conf_maxconss conflict constraints are added to the node of their validdepth; additionally (if not yet added, and if repropagation is activated), the conflict constraint that triggers the earliest repropagation is added to the node of its validdepth
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings stat dynamic problem statistics transprob transformed problem origprob original problem tree branch and bound tree reopt reoptimization data structure lp current LP data branchcand branching candidate storage eventqueue event queue cliquetable clique table data structure
Definition at line 1916 of file conflict_graphanalysis.c.
References conflictAddConflictCons(), conflictCalcMaxsize(), SCIP_ConflictSet::conflictdepth, conflictFreeTmpBdchginfos(), SCIP_Conflict::conflictsets, SCIP_Node::depth, SCIP_ConflictSet::insertdepth, SCIP_ConflictSet::nbdchginfos, SCIP_Conflict::nconflictsets, NULL, SCIP_Tree::path, SCIP_Tree::pathlen, SCIP_ConflictSet::repropagate, SCIP_ConflictSet::repropdepth, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPconflictsetFree(), SCIPdebug, SCIPnodeCutoff(), SCIPnodePropagateAgain(), SCIPsetDebugMsg, SCIPtreeGetCurrentDepth(), SCIPtreeGetFocusDepth(), SCIPvisualFoundConflict(), SCIP_ConflictSet::validdepth, and SCIP_Stat::visual.
Referenced by conflictAnalyzeLP(), SCIPconflictAnalyzePseudo(), SCIPpropagateDomains(), and solveNode().
◆ conflictEnsureConflictsetsMem()
|
static |
resizes conflictsets array to be able to store at least num entries
- Parameters
-
conflict conflict analysis data set global SCIP settings num minimal number of slots in array
Definition at line 2126 of file conflict_graphanalysis.c.
References BMSreallocMemoryArray, SCIP_Conflict::conflictsets, SCIP_Conflict::conflictsetscores, SCIP_Conflict::conflictsetssize, NULL, SCIP_ALLOC, SCIP_OKAY, and SCIPsetCalcMemGrowSize().
Referenced by conflictInsertConflictset().
◆ conflictInsertConflictset()
|
static |
inserts conflict set into sorted conflictsets array and deletes the conflict set pointer
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings conflictset pointer to conflict set to insert
Definition at line 2151 of file conflict_graphanalysis.c.
References conflictEnsureConflictsetsMem(), conflictsetCalcConflictDepth(), conflictsetCalcScore(), conflictsetIsRedundant(), SCIP_Conflict::conflictsets, SCIP_Conflict::conflictsetscores, MIN, SCIP_Conflict::nconflictsets, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPconflictsetFree(), SCIPdebug, and SCIPsetDebugMsg.
Referenced by conflictAddConflictset().
◆ conflictMarkBoundCheckPresence()
|
static |
marks bound to be present in the current conflict and returns whether a bound which is at least as tight was already member of the current conflict (i.e., the given bound change does not need to be added)
- Parameters
-
conflict conflict analysis data set global SCIP settings bdchginfo bound change to add to the conflict set relaxedbd relaxed bound
Definition at line 2247 of file conflict_graphanalysis.c.
References SCIP_Var::conflictlb, SCIP_Var::conflictlbcount, SCIP_Var::conflictrelaxedlb, SCIP_Var::conflictrelaxedub, SCIP_Var::conflictub, SCIP_Var::conflictubcount, SCIP_Conflict::count, FALSE, MAX, MIN, NULL, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_Real, SCIPABORT, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPerrorMessage, SCIPsetDebugMsg, SCIPvarGetName(), and TRUE.
Referenced by conflictAddConflictBound(), and conflictQueueBound().
◆ conflictAddConflictBound()
|
static |
puts bound change into the current conflict set
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings bdchginfo bound change to add to the conflict set relaxedbd relaxed bound
Definition at line 2336 of file conflict_graphanalysis.c.
References conflictMarkBoundCheckPresence(), SCIP_Conflict::conflictset, conflictsetAddBound(), NULL, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_OKAY, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsRedundant(), SCIPsetDebugMsg, SCIPsetIsGE(), SCIPsetIsLE(), and SCIPvarGetName().
Referenced by conflictAnalyze(), conflictCreateReconvergenceConss(), and SCIPconflictAnalyzeRemainingBdchgs().
◆ isBoundchgUseless()
|
static |
returns whether the negation of the given bound change would lead to a globally valid literal
- Parameters
-
set global SCIP settings bdchginfo bound change information
Definition at line 2379 of file conflict_graphanalysis.c.
References bound, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPsetIsFeasGE(), SCIPsetIsFeasLE(), SCIPvarGetLbGlobal(), SCIPvarGetType(), and SCIPvarGetUbGlobal().
Referenced by conflictQueueBound().
◆ conflictQueueBound()
|
static |
adds given bound change information to the conflict candidate queue
- Parameters
-
conflict conflict analysis data set global SCIP settings bdchginfo bound change information relaxedbd relaxed bound
Definition at line 2399 of file conflict_graphanalysis.c.
References SCIP_Conflict::bdchgqueue, conflictMarkBoundCheckPresence(), SCIP_Conflict::forcedbdchgqueue, isBoundchgUseless(), NULL, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_OKAY, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsRedundant(), SCIPpqueueInsert(), SCIPsetIsGE(), SCIPsetIsLE(), and SCIPvarIsBinary().
Referenced by conflictAddBound(), and conflictCreateReconvergenceConss().
◆ conflictAddBound()
|
static |
adds variable's bound to conflict candidate queue
- Parameters
-
conflict conflict analysis data blkmem block memory set global SCIP settings stat dynamic problem statistics var problem variable boundtype type of bound that was changed: lower or upper bound bdchginfo bound change info, or NULL relaxedbd relaxed bound
Definition at line 2445 of file conflict_graphanalysis.c.
References conflictQueueBound(), incVSIDS(), NULL, SCIP_BOUNDCHGTYPE_BRANCHING, SCIP_BOUNDCHGTYPE_CONSINFER, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_OKAY, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetChgtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetInferCons(), SCIPbdchginfoGetInferInfo(), SCIPbdchginfoGetInferProp(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetOldbound(), SCIPbdchginfoGetPos(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsRedundant(), SCIPconsGetName(), SCIPpropGetName(), SCIPsetDebugMsg, SCIPsetIsGE(), SCIPsetIsGT(), SCIPsetIsLE(), SCIPsetIsLT(), SCIPvarGetName(), SCIPvarGetStatus(), SCIPvarGetType(), and SCIPvarIsActive().
Referenced by SCIPconflictAddBound(), SCIPconflictAddRelaxedBound(), and SCIPconflictAnalyzeRemainingBdchgs().
◆ SCIPconflictAnalyzeRemainingBdchgs()
SCIP_RETCODE SCIPconflictAnalyzeRemainingBdchgs | ( | SCIP_CONFLICT * | conflict, |
BMS_BLKMEM * | blkmem, | ||
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_PROB * | prob, | ||
SCIP_TREE * | tree, | ||
SCIP_Bool | diving, | ||
int * | lbchginfoposs, | ||
int * | ubchginfoposs, | ||
int * | nconss, | ||
int * | nliterals, | ||
int * | nreconvconss, | ||
int * | nreconvliterals | ||
) |
applies conflict analysis starting with given bound changes, that could not be undone during previous infeasibility analysis
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings stat problem statistics prob problem data tree branch and bound tree diving are we in strong branching or diving mode? lbchginfoposs positions of currently active lower bound change information in variables' arrays ubchginfoposs positions of currently active upper bound change information in variables' arrays nconss pointer to store the number of generated conflict constraints nliterals pointer to store the number of literals in generated conflict constraints nreconvconss pointer to store the number of generated reconvergence constraints nreconvliterals pointer to store the number of literals generated reconvergence constraints
Definition at line 2503 of file conflict_graphanalysis.c.
References conflictAddBound(), conflictAddConflictBound(), conflictAnalyze(), conflictCalcMaxsize(), conflictCreateTmpBdchginfo(), SCIP_Conflict::conflictset, SCIP_ConflictSet::conflicttype, FALSE, incVSIDS(), SCIP_Var::lbchginfos, SCIP_Var::nlbchginfos, SCIP_Var::nubchginfos, NULL, SCIP_Prob::nvars, SCIP_Bool, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoIsRedundant(), SCIPconflictInit(), SCIPsetDebugMsg, SCIPvarGetLbLocal(), SCIPvarGetLbLP(), SCIPvarGetName(), SCIPvarGetStatus(), SCIPvarGetType(), SCIPvarGetUbLocal(), SCIPvarGetUbLP(), SCIP_Var::ubchginfos, SCIP_ConflictSet::usescutoffbound, and SCIP_Prob::vars.
Referenced by conflictAnalyzeLP(), and SCIPconflictAnalyzePseudo().
◆ bdchginfoIsInvalid()
|
static |
check if the bound change info (which is the potential next candidate which is queued) is valid for the current conflict analysis; a bound change info can get invalid if after this one was added to the queue, a weaker bound change was added to the queue (due the bound widening idea) which immediately makes this bound change redundant; due to the priority we did not removed that bound change info since that cost O(log(n)); hence we have to skip/ignore it now
The following situations can occur before for example the bound change info (x >= 3) is potentially popped from the queue.
Postcondition: the reason why (x >= 3) was queued is that at this time point no lower bound of x was involved yet in the current conflict or the lower bound which was involved until then was stronger, e.g., (x >= 2).
1) during the time until (x >= 3) gets potentially popped no weaker lower bound was added to the queue, in that case the conflictlbcount is valid and conflictlb is 3; that is (var->conflictlbcount == conflict->count && var->conflictlb == 3)
2) a weaker bound change info gets queued (e.g., x >= 4); this bound change is popped before (x >= 3) since it has higher priority (which is the time stamp of the bound change info and (x >= 4) has to be done after (x >= 3) during propagation or branching)
a) if (x >= 4) is popped and added to the conflict set the conflictlbcount is still valid and conflictlb is at most 4; that is (var->conflictlbcount == conflict->count && var->conflictlb >= 4); it follows that any bound change info which is stronger than (x >= 4) gets ignored (for example x >= 2)
b) if (x >= 4) is popped and resolved without introducing a new lower bound on x until (x >= 3) is a potentially candidate the conflictlbcount indicates that bound change is currently not present; that is (var->conflictlbcount != conflict->count)
c) if (x >= 4) is popped and resolved and a new lower bound on x (e.g., x >= 2) is introduced until (x >= 3) is pooped, the conflictlbcount indicates that bound change is currently present; that is (var->conflictlbcount == conflict->count); however the (x >= 3) only has be explained if conflictlb matches that one; that is (var->conflictlb == bdchginfo->newbound); otherwise it redundant/invalid.
- Parameters
-
conflict conflict analysis data bdchginfo bound change information
Definition at line 2674 of file conflict_graphanalysis.c.
References SCIP_Var::conflictlb, SCIP_Var::conflictlbcount, SCIP_Var::conflictub, SCIP_Var::conflictubcount, SCIP_Conflict::count, FALSE, NULL, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPvarIsBinary(), and TRUE.
Referenced by conflictFirstCand(), conflictRemoveCand(), conflictResolveBound(), and conflictsetAddBounds().
◆ conflictsetAddBounds()
|
static |
adds given bound changes to a conflict set
- Parameters
-
conflict conflict analysis data conflictset conflict set blkmem block memory of transformed problem set global SCIP settings bdchginfos bound changes to add to the conflict set nbdchginfos number of bound changes to add
Definition at line 2717 of file conflict_graphanalysis.c.
References bdchginfoIsInvalid(), SCIP_ConflictSet::bdchginfos, conflictsetAddBound(), conflictsetEnsureBdchginfosMem(), FALSE, SCIP_ConflictSet::hasrelaxonlyvar, MAX, MIN, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetRelaxedBound(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsTighter(), SCIPsetDebugMsg, SCIPsortIntPtrReal(), SCIPvarGetIndex(), SCIPvarGetName(), SCIPvarIsRelaxationOnly(), SCIP_ConflictSet::sortvals, and TRUE.
Referenced by conflictAddConflictset().
◆ conflictRemoveCand()
|
static |
removes and returns next conflict analysis candidate from the candidate queue
- Parameters
-
conflict conflict analysis data
Definition at line 2886 of file conflict_graphanalysis.c.
References bdchginfoIsInvalid(), SCIP_Conflict::bdchgqueue, SCIP_Var::conflictlbcount, SCIP_Var::conflictrelaxedlb, SCIP_Var::conflictrelaxedub, SCIP_Var::conflictubcount, SCIP_Conflict::forcedbdchgqueue, NULL, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_REAL_MAX, SCIP_REAL_MIN, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsRedundant(), SCIPpqueueNElems(), and SCIPpqueueRemove().
Referenced by conflictAnalyze(), and conflictCreateReconvergenceConss().
◆ conflictFirstCand()
|
static |
returns next conflict analysis candidate from the candidate queue without removing it
- Parameters
-
conflict conflict analysis data
Definition at line 2930 of file conflict_graphanalysis.c.
References bdchginfoIsInvalid(), SCIP_Conflict::bdchgqueue, SCIP_Conflict::forcedbdchgqueue, NULL, SCIP_BOUNDTYPE_LOWER, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsRedundant(), SCIPdebugMessage, SCIPpqueueFirst(), SCIPpqueueNElems(), SCIPpqueueRemove(), and SCIPvarGetName().
Referenced by conflictAnalyze(), and conflictCreateReconvergenceConss().
◆ conflictAddConflictset()
|
static |
adds the current conflict set (extended by all remaining bound changes in the queue) to the pool of conflict sets
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings stat dynamic problem statistics tree branch and bound tree validdepth minimal depth level at which the conflict set is valid diving are we in strong branching or diving mode? repropagate should the constraint trigger a repropagation? success pointer to store whether the conflict set is valid nliterals pointer to store the number of literals in the generated conflictset
Definition at line 2984 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, SCIP_Conflict::bdchgqueue, conflictInsertConflictset(), SCIP_Conflict::conflictset, conflictsetAddBounds(), conflictsetCalcInsertDepth(), conflictsetCopy(), FALSE, SCIP_Conflict::forcedbdchgqueue, SCIP_ConflictSet::insertdepth, MAX, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_Tree::path, SCIP_Tree::pathlen, SCIP_ConflictSet::relaxedbds, SCIP_ConflictSet::repropagate, SCIP_CALL, SCIP_OKAY, SCIPconflictsetFree(), SCIPdebugCheckConflict, SCIPpqueueElems(), SCIPpqueueNElems(), SCIPsetDebugMsg, SCIPtreeGetCurrentDepth(), SCIPtreeGetFocusDepth(), TRUE, and SCIP_ConflictSet::validdepth.
Referenced by conflictAnalyze(), and conflictCreateReconvergenceConss().
◆ conflictResolveBound()
|
static |
tries to resolve given bound change
- resolutions on local constraints are only applied, if the constraint is valid at the current minimal valid depth level, because this depth level is the topmost level to add the conflict constraint to anyways
- Note
- it is sufficient to explain the relaxed bound change
- Parameters
-
conflict conflict analysis data set global SCIP settings bdchginfo bound change to resolve relaxedbd the relaxed bound validdepth minimal depth level at which the conflict is valid resolved pointer to store whether the bound change was resolved
Definition at line 3083 of file conflict_graphanalysis.c.
References bdchginfoIsInvalid(), SCIP_ConflictSet::bdchginfos, SCIP_Conflict::bdchgqueue, SCIP_Conflict::conflictset, FALSE, SCIP_Conflict::forcedbdchgqueue, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_ConflictSet::relaxedbds, SCIP_BOUNDCHGTYPE_BRANCHING, SCIP_BOUNDCHGTYPE_CONSINFER, SCIP_BOUNDCHGTYPE_PROPINFER, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_Real, SCIP_SUCCESS, SCIP_VARSTATUS_AGGREGATED, SCIP_VARSTATUS_MULTAGGR, SCIP_VARSTATUS_NEGATED, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetChgtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetIdx(), SCIPbdchginfoGetInferBoundtype(), SCIPbdchginfoGetInferCons(), SCIPbdchginfoGetInferInfo(), SCIPbdchginfoGetInferProp(), SCIPbdchginfoGetInferVar(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetPos(), SCIPbdchginfoGetRelaxedBound(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsRedundant(), SCIPconsGetName(), SCIPconsGetValidDepth(), SCIPconsIsGlobal(), SCIPconsResolvePropagation(), SCIPerrorMessage, SCIPgetVarBdAtIndex(), SCIPpqueueElems(), SCIPpqueueNElems(), SCIPpropGetName(), SCIPpropResolvePropagation(), SCIPsetDebugMsg, SCIPsetDebugMsgPrint, SCIPvarGetMultaggrNVars(), SCIPvarGetName(), SCIPvarGetProbvarSum(), SCIPvarGetStatus(), SCIPvarGetType(), SCIPvarIsActive(), and TRUE.
Referenced by conflictAnalyze(), and conflictCreateReconvergenceConss().
◆ conflictClear()
|
static |
clears the conflict queue and the current conflict set
- Parameters
-
conflict conflict analysis data
Definition at line 3293 of file conflict_graphanalysis.c.
References SCIP_Conflict::bdchgqueue, SCIP_Conflict::conflictset, conflictsetClear(), SCIP_Conflict::forcedbdchgqueue, NULL, and SCIPpqueueClear().
Referenced by conflictAnalyze(), conflictCreateReconvergenceConss(), and SCIPconflictInit().
◆ SCIPconflictInit()
SCIP_RETCODE SCIPconflictInit | ( | SCIP_CONFLICT * | conflict, |
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_PROB * | prob, | ||
SCIP_CONFTYPE | conftype, | ||
SCIP_Bool | usescutoffbound | ||
) |
initializes the propagation conflict analysis by clearing the conflict candidate queue
- Parameters
-
conflict conflict analysis data set global SCIP settings stat problem statistics prob problem data conftype type of the conflict usescutoffbound depends the conflict on a cutoff bound?
Definition at line 3305 of file conflict_graphanalysis.c.
References conflictClear(), SCIP_Conflict::conflictset, SCIP_ConflictSet::conflicttype, SCIP_Conflict::count, SCIP_Stat::glbhistory, SCIP_Stat::glbhistorycrun, SCIP_Stat::lastconflictnode, SCIP_Stat::nnodes, NULL, SCIP_Prob::nvars, SCIP_CALL, SCIP_CONFTYPE_BNDEXCEEDING, SCIP_CONFTYPE_INFEASLP, SCIP_CONFTYPE_PROPAGATION, SCIP_OKAY, SCIPhistoryScaleVSIDS(), SCIPsetDebugMsg, SCIPvarScaleVSIDS(), SCIP_ConflictSet::usescutoffbound, SCIP_Prob::vars, and SCIP_Stat::vsidsweight.
Referenced by conflictCreateReconvergenceConss(), SCIPconflictAnalyzeRemainingBdchgs(), and SCIPinitConflictAnalysis().
◆ convertToActiveVar()
|
static |
convert variable and bound change to active variable
- Parameters
-
var pointer to variable set global SCIP settings boundtype pointer to type of bound that was changed: lower or upper bound bound pointer to bound to convert, or NULL
Definition at line 3372 of file conflict_graphanalysis.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_FIXED, SCIPboundtypeOpposite(), SCIPvarGetProbvarSum(), and SCIPvarGetStatus().
Referenced by SCIPconflictAddBound(), SCIPconflictAddRelaxedBound(), and SCIPconflictIsVarUsed().
◆ bdchginfoIsResolvable()
|
static |
returns whether bound change has a valid reason that can be resolved in conflict analysis
- Parameters
-
bdchginfo bound change information
Definition at line 3407 of file conflict_graphanalysis.c.
References NULL, SCIP_BOUNDCHGTYPE_CONSINFER, SCIP_BOUNDCHGTYPE_PROPINFER, SCIPbdchginfoGetChgtype(), SCIPbdchginfoGetInferProp(), and SCIPbdchginfoIsRedundant().
Referenced by addCand(), and conflictCreateReconvergenceConss().
◆ conflictCreateReconvergenceConss()
|
static |
if only one conflicting bound change of the last depth level was used, and if this can be resolved, creates GRASP-like reconvergence conflict constraints in the conflict graph up to the branching variable of this depth level
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings stat problem statistics prob problem data tree branch and bound tree diving are we in strong branching or diving mode? validdepth minimal depth level at which the initial conflict set is valid firstuip first UIP of conflict graph nreconvconss pointer to store the number of generated reconvergence constraints nreconvliterals pointer to store the number of literals generated reconvergence constraints
Definition at line 3425 of file conflict_graphanalysis.c.
References bdchginfoIsResolvable(), SCIP_ConflictSet::bdchginfos, SCIP_Conflict::bdchgqueue, conflictAddConflictBound(), conflictAddConflictset(), conflictClear(), conflictCreateTmpBdchginfo(), conflictFirstCand(), conflictQueueBound(), conflictRemoveCand(), conflictResolveBound(), SCIP_Conflict::conflictset, SCIP_ConflictSet::conflicttype, FALSE, SCIP_Conflict::forcedbdchgqueue, MIN, SCIP_ConflictSet::nbdchginfos, NULL, SCIP_Tree::path, SCIP_Tree::pathlen, SCIP_ConflictSet::relaxedbds, SCIP_Bool, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_REAL_MAX, SCIP_REAL_MIN, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetPos(), SCIPbdchginfoGetRelaxedBound(), SCIPbdchginfoGetVar(), SCIPbdchginfoIsRedundant(), SCIPboundtypeOpposite(), SCIPconflictInit(), SCIPdebugCheckConflictFrontier, SCIPpqueueNElems(), SCIPsetDebugMsg, SCIPsetIsIntegral(), SCIPtreeGetCurrentDepth(), SCIPtreeGetFocusDepth(), SCIPvarGetName(), SCIPvarIsActive(), SCIPvarIsIntegral(), and SCIP_ConflictSet::usescutoffbound.
Referenced by conflictAnalyze().
◆ conflictAnalyze()
SCIP_RETCODE conflictAnalyze | ( | SCIP_CONFLICT * | conflict, |
BMS_BLKMEM * | blkmem, | ||
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_PROB * | prob, | ||
SCIP_TREE * | tree, | ||
SCIP_Bool | diving, | ||
int | validdepth, | ||
SCIP_Bool | mustresolve, | ||
int * | nconss, | ||
int * | nliterals, | ||
int * | nreconvconss, | ||
int * | nreconvliterals | ||
) |
analyzes conflicting bound changes that were added with calls to SCIPconflictAddBound() and SCIPconflictAddRelaxedBound(), and on success, calls the conflict handlers to create a conflict constraint out of the resulting conflict set; afterwards the conflict queue and the conflict set is cleared
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings stat problem statistics prob problem data tree branch and bound tree diving are we in strong branching or diving mode? validdepth minimal depth level at which the initial conflict set is valid mustresolve should the conflict set only be used, if a resolution was applied? nconss pointer to store the number of generated conflict constraints nliterals pointer to store the number of literals in generated conflict constraints nreconvconss pointer to store the number of generated reconvergence constraints nreconvliterals pointer to store the number of literals generated reconvergence constraints
Definition at line 3661 of file conflict_graphanalysis.c.
References SCIP_ConflictSet::bdchginfos, SCIP_Conflict::bdchgqueue, SCIP_DomChgBound::boundchgs, conflictAddConflictBound(), conflictAddConflictset(), conflictClear(), conflictCreateReconvergenceConss(), conflictFirstCand(), conflictRemoveCand(), conflictResolveBound(), SCIP_Conflict::conflictset, SCIP_ConflictSet::conflicttype, SCIP_Node::domchg, SCIP_DomChg::domchgbound, FALSE, SCIP_Conflict::forcedbdchgqueue, MIN, SCIP_ConflictSet::nbdchginfos, SCIP_DomChgBound::nboundchgs, NULL, SCIP_Tree::path, SCIP_Tree::pathlen, SCIP_ConflictSet::relaxedbds, SCIP_Bool, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetPos(), SCIPbdchginfoGetRelaxedBound(), SCIPbdchginfoGetVar(), SCIPbdchginfoHasInferenceReason(), SCIPbdchginfoIsRedundant(), SCIPdebugCheckConflictFrontier, SCIPpqueueNElems(), SCIPsetAllocBufferArray, SCIPsetDebugMsg, SCIPsetFreeBufferArray, SCIPtreeGetCurrentDepth(), SCIPtreeGetFocusDepth(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetUbGlobal(), SCIPvarIsActive(), and TRUE.
Referenced by SCIPconflictAnalyze(), and SCIPconflictAnalyzeRemainingBdchgs().
◆ calcBdchgScore()
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static |
calculates the score of a bound change within a conflict
- Parameters
-
prooflhs lhs of proof constraint proofact activity of the proof constraint proofactdelta activity change proofcoef coefficient in proof constraint depth bound change depth currentdepth current depth var variable corresponding to bound change set global SCIP settings
Definition at line 3946 of file conflict_graphanalysis.c.
References MAX, NULL, SCIP_LOCKTYPE_MODEL, SCIP_Real, SCIP_VARSTATUS_COLUMN, SCIPcolGetNNonz(), SCIPvarGetCol(), SCIPvarGetNLocksDownType(), SCIPvarGetNLocksUpType(), and SCIPvarGetStatus().
Referenced by addCand().
◆ ensureCandsSize()
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static |
ensures, that candidate array can store at least num entries
- Parameters
-
set global SCIP settings cands pointer to candidate array candscores pointer to candidate score array newbounds pointer to candidate new bounds array proofactdeltas pointer to candidate proof delta array candssize pointer to size of array num minimal number of candidates to store in array
Definition at line 3991 of file conflict_graphanalysis.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIPsetCalcMemGrowSize(), and SCIPsetReallocBufferArray.
Referenced by addCand().
◆ skipRedundantBdchginfos()
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static |
after changing the global bound of a variable, the bdchginfos that are now redundant are replaced with oldbound = newbound = global bound; if the current bdchginfo is of such kind, the bound is equal to the global bound and we can ignore it by installing a -1 as the corresponding bound change info position
- Parameters
-
var problem variable lbchginfopos pointer to lower bound change information position ubchginfopos pointer to upper bound change information position
Definition at line 4025 of file conflict_graphanalysis.c.
References SCIP_Var::lbchginfos, SCIP_BdChgInfo::newbound, SCIP_Var::nlbchginfos, SCIP_Var::nubchginfos, NULL, SCIP_BdChgInfo::oldbound, SCIP_BdChgInfo::redundant, SCIPvarGetLbGlobal(), SCIPvarGetUbGlobal(), and SCIP_Var::ubchginfos.
Referenced by SCIPundoBdchgsProof().
◆ SCIPconflictAddBound()
SCIP_RETCODE SCIPconflictAddBound | ( | SCIP_CONFLICT * | conflict, |
BMS_BLKMEM * | blkmem, | ||
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_VAR * | var, | ||
SCIP_BOUNDTYPE | boundtype, | ||
SCIP_BDCHGIDX * | bdchgidx | ||
) |
adds variable's bound to conflict candidate queue
- Parameters
-
conflict conflict analysis data blkmem block memory set global SCIP settings stat dynamic problem statistics var problem variable boundtype type of bound that was changed: lower or upper bound bdchgidx bound change index (time stamp of bound change), or NULL for current time
Definition at line 4056 of file conflict_graphanalysis.c.
References conflictAddBound(), convertToActiveVar(), FALSE, NULL, scalars, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_FIXED, SCIP_VARSTATUS_MULTAGGR, SCIPbdchgidxIsEarlier(), SCIPbdchginfoGetIdx(), SCIPbdchginfoGetNewbound(), SCIPboundtypeOpposite(), SCIPconflictAddBound(), SCIPvarGetBdchgInfo(), SCIPvarGetMultaggrNVars(), SCIPvarGetMultaggrScalars(), SCIPvarGetMultaggrVars(), SCIPvarGetStatus(), and SCIPvarIsActive().
Referenced by SCIPaddConflictBd(), SCIPaddConflictBinvar(), SCIPaddConflictLb(), SCIPaddConflictUb(), SCIPconflictAddBound(), and SCIPconflictAddRelaxedBound().
◆ SCIPconflictAddRelaxedBound()
SCIP_RETCODE SCIPconflictAddRelaxedBound | ( | SCIP_CONFLICT * | conflict, |
BMS_BLKMEM * | blkmem, | ||
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_VAR * | var, | ||
SCIP_BOUNDTYPE | boundtype, | ||
SCIP_BDCHGIDX * | bdchgidx, | ||
SCIP_Real | relaxedbd | ||
) |
adds variable's bound to conflict candidate queue
- Parameters
-
conflict conflict analysis data blkmem block memory set global SCIP settings stat dynamic problem statistics var problem variable boundtype type of bound that was changed: lower or upper bound bdchgidx bound change index (time stamp of bound change), or NULL for current time relaxedbd the relaxed bound
Definition at line 4117 of file conflict_graphanalysis.c.
References SCIP_BdChgInfo::bdchgidx, conflictAddBound(), convertToActiveVar(), FALSE, MAX, MIN, NULL, SCIP_BdChgInfo::pos, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_FIXED, SCIP_VARSTATUS_MULTAGGR, SCIPbdchgidxGetPos(), SCIPbdchgidxIsEarlier(), SCIPbdchginfoGetDepth(), SCIPbdchginfoGetIdx(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetOldbound(), SCIPbdchginfoGetPos(), SCIPbdchginfoIsRedundant(), SCIPconflictAddBound(), SCIPsetDebugMsg, SCIPsetIsGE(), SCIPsetIsGT(), SCIPsetIsLE(), SCIPsetIsLT(), SCIPvarAdjustLb(), SCIPvarAdjustUb(), SCIPvarGetBdchgInfo(), SCIPvarGetBdchgInfoLb(), SCIPvarGetBdchgInfoUb(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetStatus(), SCIPvarGetUbGlobal(), and SCIPvarIsActive().
Referenced by SCIPaddConflictRelaxedBd(), SCIPaddConflictRelaxedLb(), and SCIPaddConflictRelaxedUb().
◆ SCIPconflictIsVarUsed()
SCIP_RETCODE SCIPconflictIsVarUsed | ( | SCIP_CONFLICT * | conflict, |
SCIP_VAR * | var, | ||
SCIP_SET * | set, | ||
SCIP_BOUNDTYPE | boundtype, | ||
SCIP_BDCHGIDX * | bdchgidx, | ||
SCIP_Bool * | used | ||
) |
checks if the given variable is already part of the current conflict set or queued for resolving with the same or even stronger bound
- Parameters
-
conflict conflict analysis data var problem variable set global SCIP settings boundtype type of bound for which the score should be increased bdchgidx bound change index (time stamp of bound change), or NULL for current time used pointer to store if the variable is already used
Definition at line 4281 of file conflict_graphanalysis.c.
References SCIP_Var::conflictlb, SCIP_Var::conflictlbcount, SCIP_Var::conflictub, SCIP_Var::conflictubcount, convertToActiveVar(), SCIP_Conflict::count, FALSE, NULL, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_FIXED, SCIP_VARSTATUS_MULTAGGR, SCIPABORT, SCIPerrorMessage, SCIPgetVarLbAtIndex(), SCIPgetVarUbAtIndex(), SCIPsetDebugMsg, SCIPvarGetName(), SCIPvarGetStatus(), SCIPvarIsActive(), and TRUE.
Referenced by SCIPisConflictVarUsed().
◆ addBdchg()
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static |
inserts variable's new bounds into bound change arrays
- Parameters
-
set global SCIP settings var variable to change the LP bounds for newlb new lower bound newub new upper bound oldlpbdchgs old LP bound changes used for reset the LP bound change relaxedlpbdchgs relaxed LP bound changes used for reset the LP bound change lpi pointer to LPi to access infinity of LP solver; necessary to set correct value
Definition at line 4340 of file conflict_graphanalysis.c.
References SCIP_LPBdChgs::bdchgcolinds, SCIP_LPBdChgs::bdchginds, SCIP_LPBdChgs::bdchglbs, SCIP_LPBdChgs::bdchgubs, SCIP_LPBdChgs::nbdchgs, NULL, SCIP_OKAY, SCIP_VARSTATUS_COLUMN, SCIPcolGetLPPos(), SCIPlpiInfinity(), SCIPlpiIsInfinity(), SCIPsetIsEQ(), SCIPsetIsInfinity(), SCIPvarGetCol(), SCIPvarGetLbLP(), SCIPvarGetStatus(), SCIPvarGetUbLP(), TRUE, and SCIP_LPBdChgs::usedcols.
Referenced by SCIPundoBdchgsProof().
◆ addCand()
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static |
adds variable to candidate list, if the current best bound corresponding to the proof coefficient is local; returns the array position in the candidate list, where the new candidate was inserted, or -1 if the variable can relaxed to global bounds immediately without increasing the proof's activity; the candidates are sorted with respect to the following two criteria:
- prefer bound changes that have been applied deeper in the tree, to get a more global conflict
- prefer variables with small Farkas coefficient to get rid of as many bound changes as possible
- Parameters
-
set global SCIP settings currentdepth current depth in the tree var variable to add to candidate array lbchginfopos positions of currently active lower bound change information in variable's array ubchginfopos positions of currently active upper bound change information in variable's array proofcoef coefficient of variable in infeasibility/bound proof prooflhs left hand side of infeasibility/bound proof proofact activity of infeasibility/bound proof row cands pointer to candidate array for undoing bound changes candscores pointer to candidate score array for undoing bound changes newbounds pointer to candidate new bounds array for undoing bound changes proofactdeltas pointer to proof activity increase array for undoing bound changes candssize pointer to size of cands arrays ncands pointer to count number of candidates in bound change list firstcand position of first unprocessed bound change candidate
Definition at line 4427 of file conflict_graphanalysis.c.
References SCIP_BdChgInfo::bdchgidx, bdchginfoIsResolvable(), calcBdchgScore(), SCIP_BdChgIdx::depth, ensureCandsSize(), FALSE, SCIP_Var::lbchginfos, SCIP_BdChgInfo::newbound, SCIP_Var::nlbchginfos, SCIP_Var::nubchginfos, NULL, SCIP_BdChgInfo::oldbound, QUAD, QUAD_TO_DBL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPquadprecProdQD, SCIPquadprecSumDD, SCIPsetDebugMsg, SCIPsetIsGT(), SCIPsetIsZero(), SCIPvarGetLbLocal(), SCIPvarGetLbLP(), SCIPvarGetName(), SCIPvarGetUbLocal(), SCIPvarGetUbLP(), SCIPvarIsBinary(), and SCIP_Var::ubchginfos.
Referenced by SCIPundoBdchgsProof().
◆ SCIPundoBdchgsProof()
SCIP_RETCODE SCIPundoBdchgsProof | ( | SCIP_SET * | set, |
SCIP_PROB * | prob, | ||
int | currentdepth, | ||
SCIP_Real * | proofcoefs, | ||
SCIP_Real | prooflhs, | ||
SCIP_Real * | proofact, | ||
SCIP_Real * | curvarlbs, | ||
SCIP_Real * | curvarubs, | ||
int * | lbchginfoposs, | ||
int * | ubchginfoposs, | ||
SCIP_LPBDCHGS * | oldlpbdchgs, | ||
SCIP_LPBDCHGS * | relaxedlpbdchgs, | ||
SCIP_Bool * | resolve, | ||
SCIP_LPI * | lpi | ||
) |
undoes bound changes on variables, still leaving the given infeasibility proof valid
- Parameters
-
set global SCIP settings prob problem data currentdepth current depth in the tree proofcoefs coefficients in infeasibility proof prooflhs left hand side of proof proofact current activity of proof curvarlbs current lower bounds of active problem variables curvarubs current upper bounds of active problem variables lbchginfoposs positions of currently active lower bound change information in variables' arrays ubchginfoposs positions of currently active upper bound change information in variables' arrays oldlpbdchgs old LP bound changes used for reset the LP bound change, or NULL relaxedlpbdchgs relaxed LP bound changes used for reset the LP bound change, or NULL resolve pointer to store whether the changed LP should be resolved again, or NULL lpi pointer to LPi to access infinity of LP solver; necessary to set correct values
Definition at line 4559 of file conflict_graphanalysis.c.
References addBdchg(), addCand(), FALSE, NULL, SCIP_Prob::nvars, QUAD, QUAD_TO_DBL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPquadprecProdQD, SCIPquadprecSumDD, SCIPsetAllocBufferArray, SCIPsetDebugMsg, SCIPsetFreeBufferArray, SCIPsetIsEQ(), SCIPsetIsFeasGT(), SCIPsetIsGT(), SCIPsetIsLT(), SCIPsetIsNegative(), SCIPsetIsPositive(), SCIPsetIsZero(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetProbindex(), SCIPvarGetUbGlobal(), SCIPvarIsInLP(), skipRedundantBdchginfos(), TRUE, and SCIP_Prob::vars.
Referenced by SCIPconflictAnalyzePseudo(), undoBdchgsDualfarkas(), and undoBdchgsDualsol().
◆ undoBdchgsDualfarkas()
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static |
analyzes an infeasible LP and undoes additional bound changes while staying infeasible
- Parameters
-
set global SCIP settings prob problem data lp LP data currentdepth current depth in the tree curvarlbs current lower bounds of active problem variables curvarubs current upper bounds of active problem variables lbchginfoposs positions of currently active lower bound change information in variables' arrays ubchginfoposs positions of currently active upper bound change information in variables' arrays oldlpbdchgs old LP bound changes used for reset the LP bound change, or NULL relaxedlpbdchgs relaxed LP bound changes used for reset the LP bound change, or NULL valid pointer to store whether the unfixings are valid resolve pointer to store whether the changed LP should be resolved again farkascoefs coefficients in the proof constraint farkaslhs lhs of the proof constraint farkasactivity maximal activity of the proof constraint
Definition at line 4771 of file conflict_graphanalysis.c.
References SCIP_Lp::cutoffbound, FALSE, SCIP_Lp::flushed, NULL, SCIP_CALL, SCIP_OKAY, SCIPlpGetLPI(), SCIPsetDebugMsg, SCIPsetIsFeasGT(), SCIPundoBdchgsProof(), SCIP_Lp::solved, and TRUE.
Referenced by SCIPrunBoundHeuristic().
◆ lpbdchgsCreate()
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static |
create conflict LP bound change data structure
- Parameters
-
lpbdchgs pointer to store the conflict LP bound change data structure set global SCIP settings ncols number of columns
Definition at line 4832 of file conflict_graphanalysis.c.
References BMSclearMemoryArray, SCIP_CALL, SCIP_OKAY, SCIPsetAllocBuffer, and SCIPsetAllocBufferArray.
Referenced by SCIPrunBoundHeuristic().
◆ ensureSidechgsSize()
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static |
ensures, that side change arrays can store at least num entries
- Parameters
-
set global SCIP settings sidechginds pointer to side change index array sidechgoldlhss pointer to side change old left hand sides array sidechgoldrhss pointer to side change old right hand sides array sidechgnewlhss pointer to side change new left hand sides array sidechgnewrhss pointer to side change new right hand sides array sidechgssize pointer to size of side change arrays num minimal number of entries to be able to store in side change arrays
Definition at line 4859 of file conflict_graphanalysis.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIPsetCalcMemGrowSize(), and SCIPsetReallocBufferArray.
Referenced by addSideRemoval().
◆ addSideRemoval()
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static |
adds removal of row's side to side change arrays; finite sides are only replaced by near infinite sides, such that the row's sense in the LP solver is not changed
- Parameters
-
set global SCIP settings row LP row to change the sides for lpiinfinity value treated as infinity in LP solver sidechginds pointer to side change index array sidechgoldlhss pointer to side change old left hand sides array sidechgoldrhss pointer to side change old right hand sides array sidechgnewlhss pointer to side change new left hand sides array sidechgnewrhss pointer to side change new right hand sides array sidechgssize pointer to size of side change arrays nsidechgs pointer to number of used slots in side change arrays
Definition at line 4898 of file conflict_graphanalysis.c.
References ensureSidechgsSize(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIProwGetConstant(), SCIProwGetLhs(), SCIProwGetLPPos(), SCIProwGetRhs(), and SCIPsetIsInfinity().
Referenced by SCIPrunBoundHeuristic().
◆ lpbdchgsReset()
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static |
reset conflict LP bound change data structure
- Parameters
-
lpbdchgs conflict LP bound change data structure ncols number of columns
Definition at line 4972 of file conflict_graphanalysis.c.
References BMSclearMemoryArray, SCIP_LPBdChgs::nbdchgs, NULL, and SCIP_LPBdChgs::usedcols.
Referenced by SCIPrunBoundHeuristic().
◆ lpbdchgsFree()
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static |
free conflict LP bound change data structure
- Parameters
-
lpbdchgs pointer to store the conflict LP bound change data structure set global SCIP settings
Definition at line 4985 of file conflict_graphanalysis.c.
References SCIPsetFreeBuffer, and SCIPsetFreeBufferArray.
Referenced by SCIPrunBoundHeuristic().
◆ undoBdchgsDualsol()
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static |
analyzes an LP exceeding the objective limit and undoes additional bound changes while staying beyond the objective limit
- Parameters
-
set global SCIP settings prob problem data lp LP data currentdepth current depth in the tree curvarlbs current lower bounds of active problem variables curvarubs current upper bounds of active problem variables lbchginfoposs positions of currently active lower bound change information in variables' arrays ubchginfoposs positions of currently active upper bound change information in variables' arrays oldlpbdchgs old LP bound changes used for reset the LP bound change, or NULL relaxedlpbdchgs relaxed LP bound changes used for reset the LP bound change, or NULL valid pointer to store whether the unfixings are valid resolve pointer to store whether the changed LP should be resolved again dualcoefs coefficients in the proof constraint duallhs lhs of the proof constraint dualactivity maximal activity of the proof constraint
Definition at line 5003 of file conflict_graphanalysis.c.
References SCIP_Lp::cutoffbound, FALSE, SCIP_Lp::flushed, NULL, SCIP_CALL, SCIP_OKAY, SCIPlpGetLPI(), SCIPsetDebugMsg, SCIPsetIsFeasGT(), SCIPundoBdchgsProof(), SCIP_Lp::solved, and TRUE.
Referenced by SCIPrunBoundHeuristic().
◆ SCIPrunBoundHeuristic()
SCIP_RETCODE SCIPrunBoundHeuristic | ( | SCIP_CONFLICT * | conflict, |
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_PROB * | origprob, | ||
SCIP_PROB * | transprob, | ||
SCIP_TREE * | tree, | ||
SCIP_REOPT * | reopt, | ||
SCIP_LP * | lp, | ||
SCIP_LPI * | lpi, | ||
BMS_BLKMEM * | blkmem, | ||
SCIP_Real * | proofcoefs, | ||
SCIP_Real * | prooflhs, | ||
SCIP_Real * | proofactivity, | ||
SCIP_Real * | curvarlbs, | ||
SCIP_Real * | curvarubs, | ||
int * | lbchginfoposs, | ||
int * | ubchginfoposs, | ||
int * | iterations, | ||
SCIP_Bool | marklpunsolved, | ||
SCIP_Bool * | dualproofsuccess, | ||
SCIP_Bool * | valid | ||
) |
try to find a subset of changed bounds leading to an infeasible LP
- call undoBdchgsDualfarkas() or undoBdchgsDualsol() -> update lb/ubchginfoposs arrays -> store additional changes in bdchg and curvarlbs/ubs arrays -> apply additional changes to the LPI
- (optional) if additional bound changes were undone: -> resolve LP -> goto 1.
- redo all bound changes in the LPI to restore the LPI to its original state
- analyze conflict -> put remaining changed bounds (see lb/ubchginfoposs arrays) into starting conflict set
- Parameters
-
conflict conflict data set global SCIP settings stat problem statistics origprob original problem transprob transformed problem tree branch and bound tree reopt reoptimization data lp LP data lpi LPI data blkmem block memory proofcoefs coefficients in the proof constraint prooflhs lhs of the proof constraint proofactivity maximal activity of the proof constraint curvarlbs current lower bounds of active problem variables curvarubs current upper bounds of active problem variables lbchginfoposs positions of currently active lower bound change information in variables' arrays ubchginfoposs positions of currently active upper bound change information in variables' arrays iterations pointer to store the total number of LP iterations used marklpunsolved whether LP should be marked unsolved after analysis (needed for strong branching) dualproofsuccess pointer to store success result of dual proof analysis valid pointer to store whether the result is still a valid proof
Definition at line 5069 of file conflict_graphanalysis.c.
References addSideRemoval(), SCIP_LPBdChgs::bdchginds, SCIP_LPBdChgs::bdchglbs, SCIP_LPBdChgs::bdchgubs, BMSclearMemoryArray, SCIP_Stat::conflictlptime, SCIP_Conflict::conflictset, SCIP_ConflictSet::conflicttype, SCIP_Lp::dualchecked, SCIP_Lp::dualfeasible, FALSE, lpbdchgsCreate(), lpbdchgsFree(), lpbdchgsReset(), SCIP_Lp::lpiitlim, SCIP_Lp::lpiobjlim, SCIP_Lp::lpobjval, SCIP_Lp::lpsolstat, SCIP_LPBdChgs::nbdchgs, SCIP_Stat::nconflictlpiterations, SCIP_Stat::nconflictlps, NULL, SCIP_Lp::primalchecked, SCIP_Lp::primalfeasible, r, SCIP_Bool, SCIP_CALL, SCIP_CONFTYPE_INFEASLP, SCIP_INVALID, SCIP_LONGINT_FORMAT, SCIP_LPERROR, SCIP_LPPAR_LPITLIM, SCIP_LPPAR_OBJLIM, SCIP_LPSOLSTAT_NOTSOLVED, SCIP_OKAY, SCIP_Real, SCIPaggrRowCreate(), SCIPaggrRowFree(), SCIPaggrRowGetInds(), SCIPaggrRowGetNNz(), SCIPaggrRowGetProbvarValue(), SCIPaggrRowGetRhs(), SCIPclockStart(), SCIPclockStop(), SCIPconflictAnalyzeDualProof(), SCIPgetDualProof(), SCIPgetFarkasProof(), SCIPlpDivingObjChanged(), SCIPlpGetNCols(), SCIPlpGetNRows(), SCIPlpGetRows(), SCIPlpiChgBounds(), SCIPlpiChgSides(), SCIPlpiGetIterations(), SCIPlpiGetObjval(), SCIPlpiInfinity(), SCIPlpiIsDualFeasible(), SCIPlpiIsObjlimExc(), SCIPlpiIsPrimalInfeasible(), SCIPlpiSetIntpar(), SCIPlpiSetRealpar(), SCIPlpiSolveDual(), SCIPprobAllColsInLP(), SCIPprobGetNVars(), SCIPprobGetVars(), SCIProwGetLhs(), SCIProwGetLPPos(), SCIProwGetName(), SCIProwGetRhs(), SCIProwIsLocal(), SCIPsetAllocBufferArray, SCIPsetDebugMsg, SCIPsetFreeBufferArray, SCIPtreeGetCurrentDepth(), SCIPtreeGetEffectiveRootDepth(), SCIPvarGetProbindex(), SCIP_Lp::solved, undoBdchgsDualfarkas(), and undoBdchgsDualsol().
Referenced by conflictAnalyzeLP().
◆ SCIPconflictAnalyze()
SCIP_RETCODE SCIPconflictAnalyze | ( | SCIP_CONFLICT * | conflict, |
BMS_BLKMEM * | blkmem, | ||
SCIP_SET * | set, | ||
SCIP_STAT * | stat, | ||
SCIP_PROB * | prob, | ||
SCIP_TREE * | tree, | ||
int | validdepth, | ||
SCIP_Bool * | success | ||
) |
analyzes conflicting bound changes that were added with calls to SCIPconflictAddBound(), and on success, calls the conflict handlers to create a conflict constraint out of the resulting conflict set; updates statistics for propagation conflict analysis
- Parameters
-
conflict conflict analysis data blkmem block memory of transformed problem set global SCIP settings stat problem statistics prob problem data tree branch and bound tree validdepth minimal depth level at which the initial conflict set is valid success pointer to store whether a conflict constraint was created, or NULL
Definition at line 5448 of file conflict_graphanalysis.c.
References SCIP_Conflict::bdchgqueue, conflictAnalyze(), conflictCalcMaxsize(), SCIP_Conflict::conflictset, FALSE, SCIP_Conflict::forcedbdchgqueue, SCIP_ConflictSet::nbdchginfos, SCIP_Conflict::npropcalls, SCIP_Conflict::npropconfconss, SCIP_Conflict::npropconfliterals, SCIP_Conflict::npropreconvconss, SCIP_Conflict::npropreconvliterals, SCIP_Conflict::npropsuccess, NULL, SCIP_Conflict::propanalyzetime, SCIP_CALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), SCIPconflictApplicable(), SCIPpqueueNElems(), SCIPsetDebugMsg, SCIPtreeGetCurrentDepth(), and TRUE.
Referenced by SCIPanalyzeConflict(), and SCIPanalyzeConflictCons().