Add a way to use the presolver papilo, which is a free presolver from…

… the SCIP project. Not much work has been done recently in Coin on pre-processing for integer problems and this does well on some problems. To use see instructions at end of CglPreProcess.cpp and add -DCBC_USE_PAPILO=1 to build of Cbc.
coin-or · Sep 10, 2024 · 729e751 · 729e751
1 parent f657200
commit 729e751
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Showing 3 changed files with 94 additions and 3 deletions.
diff --git a/src/CbcParameters.cpp b/src/CbcParameters.cpp
@@ -1271,9 +1271,20 @@ void CbcParameters::addCbcSolverKwdParams() {
  parameters_[CbcParam::PREPROCESS]->appendKwd("strategy", CbcParameters::IPPStrategy);
  parameters_[CbcParam::PREPROCESS]->appendKwd("aggregate", CbcParameters::IPPAggregate);
  parameters_[CbcParam::PREPROCESS]->appendKwd("forcesos", CbcParameters::IPPForceSOS);
+#if CBC_USE_PAPILO
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilob!egin", CbcParameters::IPPPapilo);
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilo2b!egin", CbcParameters::IPPPapilo2);
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilo", CbcParameters::IPPPapiloEnd);
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilo2", CbcParameters::IPPPapilo2End);
+#endif
  parameters_[CbcParam::PREPROCESS]->appendKwd("stop!aftersaving", CbcParameters::IPPStopAfterSaving);
  parameters_[CbcParam::PREPROCESS]->appendKwd("equalallstop", CbcParameters::IPPEqualAllStop);
-
+#if CBC_USE_PAPILO
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilobeginstop", CbcParameters::IPPPapiloStop);
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilo2beginstop", CbcParameters::IPPPapilo2Stop);
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilostop", CbcParameters::IPPPapiloStopEnd);
+ parameters_[CbcParam::PREPROCESS]->appendKwd("papilo2stop", CbcParameters::IPPPapilo2StopEnd);
+#endif
  parameters_[CbcParam::SOSPRIORITIZE]->setup(
  "sosP!rioritize", "How to deal with SOS priorities", 
  "This sets priorities for SOS. Values 'high' and 'low' just set a "

diff --git a/src/CbcParameters.hpp b/src/CbcParameters.hpp
@@ -137,6 +137,16 @@ class CBCLIB_EXPORT CbcParameters {
  IPPForceSOS,
  IPPStopAfterSaving,
  IPPEqualAllStop,
+#if CBC_USE_PAPILO
+ IPPPapilo,
+ IPPPapilo2,
+ IPPPapiloEnd,
+ IPPPapilo2End,
+ IPPPapiloStop,
+ IPPPapilo2Stop,
+ IPPPapiloStopEnd,
+ IPPPapilo2StopEnd,
+#endif
  IPPEndMarker
  };
 

diff --git a/src/CbcSolver.cpp b/src/CbcSolver.cpp
@@ -1430,7 +1430,7 @@ int CbcMain1(std::deque<std::string> inputQueue, CbcModel &model,
  int redsplit2Mode = CbcParameters::CGOff;
  assert (parameters[CbcParam::REDSPLIT2CUTS]->modeVal()==redsplit2Mode);
 
- CglGMI GMIGen;
+ CglGMI GMIGen; 
  int GMIMode = parameters[CbcParam::GMICUTS]->modeVal();
 
  std::string cgraphMode = "on";
@@ -4827,9 +4827,73 @@ int CbcMain1(std::deque<std::string> inputQueue, CbcModel &model,
  if (keepPPN)
  babModel_->setKeepNamesPreproc(1);
  setPreProcessingMode(saveSolver,1);
+#if CBC_USE_PAPILO
+ extern void zapPapilo(int pOptions,CglPreProcess * process);
+ int pOptions = 0;
+ int tune2 = preProcess;
+ // Convert to minimize if papilo
+ bool maximize = false;
+ if (tune2>11) {
+ OsiClpSolverInterface * clpSolver =
+ dynamic_cast<OsiClpSolverInterface *>(saveSolver);
+ if (clpSolver->getObjSense()==-1.0) {
+ maximize = true;
+ clpSolver->setObjSense(1.0);
+ double objOffset;
+ clpSolver->getDblParam(OsiObjOffset, objOffset);
+ int numberColumns = clpSolver->getNumCols();
+ double * objective = clpSolver->getModelPtr()->objective();
+ for (int i=0;i<numberColumns;i++)
+ objective[i] = -objective[i];
+ clpSolver->setDblParam(OsiObjOffset, -objOffset);
+ }
+ bool stopAfter = false;
+ if (tune2>15) {
+ preProcess=10; // say stop
+ tune2 -=4;
+ } else {
+ preProcess=1;
+ }
+#ifdef CBC_THREAD
+ pOptions = (tune2&1) != 0 ? 2 : 0; // bug when 1???
+#endif
+ if ((tune2&2) == 0)
+ pOptions|= 8; // at beginning
+ else
+ pOptions|= 16; // at end
+ }
+ zapPapilo(pOptions,&process);
+#endif
  solver2 = process.preProcessNonDefault(*saveSolver, translate[preProcess], numberPasses,
  tunePreProcess);
- setPreProcessingMode(saveSolver,0);
+ setPreProcessingMode(saveSolver,0);
+#if CBC_USE_PAPILO
+ // Convert back
+ if (maximize) {
+ OsiClpSolverInterface * clpSolver =
+ dynamic_cast<OsiClpSolverInterface *>(saveSolver);
+ double objOffset;
+ clpSolver->setObjSense(-1.0);
+ clpSolver->getDblParam(OsiObjOffset, objOffset);
+ int numberColumns = clpSolver->getNumCols();
+ double * objective = clpSolver->getModelPtr()->objective();
+ for (int i=0;i<numberColumns;i++)
+ objective[i] = -objective[i];
+ clpSolver->setDblParam(OsiObjOffset, -objOffset);
+ if (solver2) {
+ OsiClpSolverInterface * clpSolver =
+ dynamic_cast<OsiClpSolverInterface *>(solver2);
+ double objOffset;
+ clpSolver->setObjSense(-1.0);
+ clpSolver->getDblParam(OsiObjOffset, objOffset);
+ int numberColumns = clpSolver->getNumCols();
+ double * objective = clpSolver->getModelPtr()->objective();
+ for (int i=0;i<numberColumns;i++)
+ objective[i] = -objective[i];
+ clpSolver->setDblParam(OsiObjOffset, -objOffset);
+ }
+ }
+#endif
  if (solver2) {
  setPreProcessingMode(solver2, 0);
  model_.setOriginalColumns(process.originalColumns(),
@@ -7722,6 +7786,12 @@ int CbcMain1(std::deque<std::string> inputQueue, CbcModel &model,
 #ifdef CBC_THREAD
  int numberThreads = parameters[CbcParam::THREADS]->intVal();
  babModel_->setNumberThreads(numberThreads % 100);
+ // switch off deterministic if large problem and fastNodeDepth>0
+ if (numberThreads/100==2) {
+ numberThreads -= 100;
+ if (babModel_->fastNodeDepth()>0 && babModel_->solver()->getNumRows()>2000) 
+ babModel_->setFastNodeDepth(-999);
+ }
  babModel_->setThreadMode((numberThreads%1000) / 100);
 #ifdef CBC_USE_OPENMP
  if (numberThreads>100) {