Ejemplo n.º 1
0
int main(int argc, char **argv) 
{
  char *f_name_lp, *last_dot_pos, f_name[256], *f_name_pos;
  int i, ncol;

  if((argc < 2) || (argc > 2)) {
    printf("### ERROR: main(): Usage: One of the following\ncgl_data_test input_file_name.mps\ncgl_data_test input_file_name.lp\n");
    exit(1);
  }

  f_name_lp = strdup(argv[1]);
  f_name_pos = strrchr(f_name_lp, '/');
  if(f_name_pos != NULL) {
    strcpy(f_name, &(f_name_pos[1]));
  }
  else {
    strcpy(f_name, f_name_lp);
  }
  last_dot_pos = strrchr(f_name, '.');
  if(last_dot_pos != NULL) {
    last_dot_pos = '\0';
  }

  OsiClpSolverInterface *clp = new OsiClpSolverInterface;
  clp->messageHandler()->setLogLevel(0);
  if(strcmp(&(f_name_lp[strlen(f_name_lp)-3]), ".lp") == 0) {
    clp->readLp(f_name_lp);    
  }
  else {
    if(strcmp(&(f_name_lp[strlen(f_name_lp)-4]), ".mps") == 0) {
      clp->readMps(f_name_lp);    
    }
    else {
      printf("### ERROR: unrecognized file type\n");
      exit(1);
    }
  }
  ncol = clp->getNumCols();
  clp->initialSolve();

  printf("LP value: %12.2f\n", clp->getObjValue());

  OsiCuts cuts;

  // Define parameters for CglRedSplit generator
  CglParam cpar;
  cpar.setMAX_SUPPORT(ncol+1);
  CglRedSplitParam rspar(cpar);

  // Create a cut generator with the given parameters
  CglRedSplit cutGen(rspar);

  char *colType = new char[ncol];
  for(i=0; i<ncol; i++) {
    if(clp->isContinuous(i)) {
      colType[i] = 'C';
    }
    else {
      colType[i] = 'I';
    }
  }

  int round, max_rounds = 10;
  for(round=0; round<max_rounds; round++) {
    cutGen.generateCuts(*clp, cuts);

    int ncuts = cuts.sizeRowCuts();

    const OsiRowCut **newRowCuts = new const OsiRowCut * [ncuts];
    for(i=0; i<ncuts; i++) {
      newRowCuts[i] = &cuts.rowCut(i); 
    }
    clp->applyRowCuts(ncuts, newRowCuts);
    delete[] newRowCuts;

    printf("round %4d: %4d generated cuts  new objective value: %12.2f\n", 
	   round, ncuts, clp->getObjValue());

    clp->resolve();  

    if(clp->isAbandoned()) {
      printf("###ERROR: Numerical difficulties in Solver\n");
      exit(1);
    }
  
    if(clp->isProvenPrimalInfeasible()) {
      printf("### WARNING: Problem is infeasible\n");
      exit(1);
    }
  }

  delete clp;
  free(f_name_lp);
  delete[] colType;

  return(0);
}
Ejemplo n.º 2
0
int main (int argc, const char *argv[])
{

  // Define your favorite OsiSolver
  
  OsiClpSolverInterface solver1;

  // Read in model using argv[1]
  // and assert that it is a clean model
  std::string mpsFileName;
#if defined(SAMPLEDIR)
  mpsFileName = SAMPLEDIR "/p0033.mps";
#else
  if (argc < 2) {
    fprintf(stderr, "Do not know where to find sample MPS files.\n");
    exit(1);
  }
#endif
  if (argc>=2) mpsFileName = argv[1];
  int numMpsReadErrors = solver1.readMps(mpsFileName.c_str(),"");
  assert(numMpsReadErrors==0);
  double time1 = CoinCpuTime();
  OsiClpSolverInterface solverSave = solver1;

  /* Options are:
     preprocess to do preprocessing
     time in minutes
     if 2 parameters and numeric taken as time
  */
  bool preProcess=false;
  double minutes=-1.0;
  int nGoodParam=0;
  for (int iParam=2; iParam<argc;iParam++) {
    if (!strcmp(argv[iParam],"preprocess")) {
      preProcess=true;
      nGoodParam++;
    } else if (!strcmp(argv[iParam],"time")) {
      if (iParam+1<argc&&isdigit(argv[iParam+1][0])) {
        minutes=atof(argv[iParam+1]);
        if (minutes>=0.0) {
          nGoodParam+=2;
          iParam++; // skip time
        }
      }
    }
  }
  if (nGoodParam==0&&argc==3&&isdigit(argv[2][0])) {
    // If time is given then stop after that number of minutes
    minutes = atof(argv[2]);
    if (minutes>=0.0) 
      nGoodParam=1;
  }
  if (nGoodParam!=argc-2&&argc>=2) {
    printf("Usage <file> [preprocess] [time <minutes>] or <file> <minutes>\n");
    exit(1);
  }
  // Reduce printout
  solver1.setHintParam(OsiDoReducePrint,true,OsiHintTry);
  // See if we want preprocessing
  OsiSolverInterface * solver2=&solver1;
  CglPreProcess process;
  // Never do preprocessing until dual tests out as can fix incorrectly
  preProcess=false;
  if (preProcess) {
    /* Do not try and produce equality cliques and
       do up to 5 passes */
    solver2 = process.preProcess(solver1,false,5);
    if (!solver2) {
      printf("Pre-processing says infeasible\n");
      exit(2);
    }
    solver2->resolve();
  }
  // Turn L rows into cuts
  CglStoredUser stored;
 {
  int numberRows = solver2->getNumRows();

  int * whichRow = new int[numberRows];
  // get row copy
  const CoinPackedMatrix * rowCopy = solver2->getMatrixByRow();
  const int * column = rowCopy->getIndices();
  const int * rowLength = rowCopy->getVectorLengths();
  const CoinBigIndex * rowStart = rowCopy->getVectorStarts();
  const double * rowLower = solver2->getRowLower();
  const double * rowUpper = solver2->getRowUpper();
  const double * element = rowCopy->getElements();
  int iRow,nDelete=0;
  for (iRow=0;iRow<numberRows;iRow++) {
    if (rowLower[iRow]<-1.0e20||rowUpper[iRow]>1.0e20) {
      // take out
      whichRow[nDelete++]=iRow;
    }
  }
  // leave some rows to avoid empty problem (Gomory does not like)
  nDelete = CoinMax(CoinMin(nDelete,numberRows-5),0);
  for (int jRow=0;jRow<nDelete;jRow++) {
    iRow=whichRow[jRow];
    int start = rowStart[iRow];
    stored.addCut(rowLower[iRow],rowUpper[iRow],rowLength[iRow],
		  column+start,element+start);
  }
  /* The following is problem specific.
     Normally cuts are deleted if slack on cut basic.
     On some problems you may wish to leave cuts in as long
     as slack value zero
  */
  int numberCuts=stored.sizeRowCuts();
  for (int iCut=0;iCut<numberCuts;iCut++) {
    //stored.mutableRowCutPointer(iCut)->setEffectiveness(1.0e50);
  }
  solver2->deleteRows(nDelete,whichRow);
  delete [] whichRow;
 }
  CbcModel model(*solver2);
  model.solver()->setHintParam(OsiDoReducePrint,true,OsiHintTry);
  // Set up some cut generators and defaults
  // Probing first as gets tight bounds on continuous

  CglProbing generator1;
  generator1.setUsingObjective(true);
  generator1.setMaxPass(1);
  generator1.setMaxPassRoot(5);
  // Number of unsatisfied variables to look at
  generator1.setMaxProbe(10);
  generator1.setMaxProbeRoot(1000);
  // How far to follow the consequences
  generator1.setMaxLook(50);
  generator1.setMaxLookRoot(500);
  // Only look at rows with fewer than this number of elements
  generator1.setMaxElements(200);
  generator1.setRowCuts(3);

  CglGomory generator2;
  // try larger limit
  generator2.setLimit(300);

  CglKnapsackCover generator3;

  CglRedSplit generator4;
  // try larger limit
  generator4.setLimit(200);

  CglClique generator5;
  generator5.setStarCliqueReport(false);
  generator5.setRowCliqueReport(false);

  CglMixedIntegerRounding2 mixedGen;
  CglFlowCover flowGen;
  
  // Add in generators
  // Experiment with -1 and -99 etc
  // This is just for one particular model
  model.addCutGenerator(&generator1,-1,"Probing");
  //model.addCutGenerator(&generator2,-1,"Gomory");
  model.addCutGenerator(&generator2,1,"Gomory");
  model.addCutGenerator(&generator3,-1,"Knapsack");
  // model.addCutGenerator(&generator4,-1,"RedSplit");
  //model.addCutGenerator(&generator5,-1,"Clique");
  model.addCutGenerator(&generator5,1,"Clique");
  model.addCutGenerator(&flowGen,-1,"FlowCover");
  model.addCutGenerator(&mixedGen,-1,"MixedIntegerRounding");
  // Add stored cuts (making sure at all depths)
  model.addCutGenerator(&stored,1,"Stored",true,false,false,-100,1,-1);
  
  int numberGenerators = model.numberCutGenerators();
  int iGenerator;
  // Say we want timings
  for (iGenerator=0;iGenerator<numberGenerators;iGenerator++) {
    CbcCutGenerator * generator = model.cutGenerator(iGenerator);
    generator->setTiming(true);
  }
  OsiClpSolverInterface * osiclp = dynamic_cast< OsiClpSolverInterface*> (model.solver());
  // go faster stripes
  if (osiclp) { 
    if(osiclp->getNumRows()<300&&osiclp->getNumCols()<500) {
      //osiclp->setupForRepeatedUse(2,0);
      osiclp->setupForRepeatedUse(0,0);
    }
    // Don't allow dual stuff
    osiclp->setSpecialOptions(osiclp->specialOptions()|262144);
  } 
  // Uncommenting this should switch off all CBC messages
  // model.messagesPointer()->setDetailMessages(10,10000,NULL);
  // No heuristics
  // Do initial solve to continuous
  model.initialSolve();
  /*  You need the next few lines -
      a) so that cut generator will always be called again if it generated cuts
      b) it is known that matrix is not enough to define problem so do cuts even
         if it looks integer feasible at continuous optimum.
      c) a solution found by strong branching will be ignored.
      d) don't recompute a solution once found
  */
  // Make sure cut generator called correctly (a)
  iGenerator=numberGenerators-1;
  model.cutGenerator(iGenerator)->setMustCallAgain(true);
  // Say cuts needed at continuous (b)
  OsiBabSolver oddCuts;
  oddCuts.setSolverType(4);
  // owing to bug must set after initialSolve
  model.passInSolverCharacteristics(&oddCuts);
  // Say no to all solutions by strong branching (c)
  CbcFeasibilityNoStrong noStrong;
  model.setProblemFeasibility(noStrong);
  // Say don't recompute solution d)
  model.setSpecialOptions(4);

  // Could tune more
  double objValue = model.solver()->getObjSense()*model.solver()->getObjValue();
  double minimumDropA=CoinMin(1.0,fabs(objValue)*1.0e-3+1.0e-4);
  double minimumDrop= fabs(objValue)*1.0e-4+1.0e-4;
  printf("min drop %g (A %g)\n",minimumDrop,minimumDropA);
  model.setMinimumDrop(minimumDrop);

  if (model.getNumCols()<500)
    model.setMaximumCutPassesAtRoot(-100); // always do 100 if possible
  else if (model.getNumCols()<5000)
    model.setMaximumCutPassesAtRoot(100); // use minimum drop
  else
    model.setMaximumCutPassesAtRoot(20);
  model.setMaximumCutPasses(10);
  //model.setMaximumCutPasses(2);

  // Switch off strong branching if wanted
  // model.setNumberStrong(0);
  // Do more strong branching if small
  if (model.getNumCols()<5000)
    model.setNumberStrong(10);
  model.setNumberStrong(20);
  //model.setNumberStrong(5);
  model.setNumberBeforeTrust(5);

  model.solver()->setIntParam(OsiMaxNumIterationHotStart,100);

  // If time is given then stop after that number of minutes
  if (minutes>=0.0) {
    std::cout<<"Stopping after "<<minutes<<" minutes"<<std::endl;
    model.setDblParam(CbcModel::CbcMaximumSeconds,60.0*minutes);
  }
  // Switch off most output
  if (model.getNumCols()<30000) {
    model.messageHandler()->setLogLevel(1);
    //model.solver()->messageHandler()->setLogLevel(0);
  } else {
    model.messageHandler()->setLogLevel(2);
    model.solver()->messageHandler()->setLogLevel(1);
  }
  //model.messageHandler()->setLogLevel(2);
  //model.solver()->messageHandler()->setLogLevel(2);
  //model.setPrintFrequency(50);
  //#define DEBUG_CUTS
#ifdef DEBUG_CUTS
  // Set up debugger by name (only if no preprocesing)
  if (!preProcess) {
    std::string problemName ;
    model.solver()->getStrParam(OsiProbName,problemName) ;
    model.solver()->activateRowCutDebugger(problemName.c_str()) ;
  }
#endif
  // Do complete search
  
  model.branchAndBound();

  std::cout<<mpsFileName<<" took "<<CoinCpuTime()-time1<<" seconds, "
	   <<model.getNodeCount()<<" nodes with objective "
	   <<model.getObjValue()
	   <<(!model.status() ? " Finished" : " Not finished")
	   <<std::endl;

  // Print more statistics
  std::cout<<"Cuts at root node changed objective from "<<model.getContinuousObjective()
	   <<" to "<<model.rootObjectiveAfterCuts()<<std::endl;

  for (iGenerator=0;iGenerator<numberGenerators;iGenerator++) {
    CbcCutGenerator * generator = model.cutGenerator(iGenerator);
    std::cout<<generator->cutGeneratorName()<<" was tried "
	     <<generator->numberTimesEntered()<<" times and created "
	     <<generator->numberCutsInTotal()<<" cuts of which "
	     <<generator->numberCutsActive()<<" were active after adding rounds of cuts";
    if (generator->timing())
      std::cout<<" ( "<<generator->timeInCutGenerator()<<" seconds)"<<std::endl;
    else
      std::cout<<std::endl;
  }
  // Print solution if finished - we can't get names from Osi! - so get from OsiClp

  if (model.getMinimizationObjValue()<1.0e50) {
    // post process
    OsiSolverInterface * solver;
    if (preProcess) {
      process.postProcess(*model.solver());
      // Solution now back in solver1
      solver = & solver1;
    } else {
      solver = model.solver();
    }
    int numberColumns = solver->getNumCols();
    
    const double * solution = solver->getColSolution();

    // Get names from solver1 (as OsiSolverInterface may lose)
    std::vector<std::string> columnNames = *solver1.getModelPtr()->columnNames();
    
    int iColumn;
    std::cout<<std::setiosflags(std::ios::fixed|std::ios::showpoint)<<std::setw(14);
    
    std::cout<<"--------------------------------------"<<std::endl;
    for (iColumn=0;iColumn<numberColumns;iColumn++) {
      double value=solution[iColumn];
      if (fabs(value)>1.0e-7&&solver->isInteger(iColumn)) {
	std::cout<<std::setw(6)<<iColumn<<" "
                 <<columnNames[iColumn]<<" "
                 <<value<<std::endl;
	solverSave.setColLower(iColumn,value);
	solverSave.setColUpper(iColumn,value);
      }
    }
    std::cout<<"--------------------------------------"<<std::endl;
  
    std::cout<<std::resetiosflags(std::ios::fixed|std::ios::showpoint|std::ios::scientific);
    solverSave.initialSolve();
  }
  return 0;
}