void* problem_convert_to_osi(Problem *p)
{
int i;
double rowLb, rowUb;
OsiSolverInterface *solver = new OsiClpSolverInterface();
CoinBuild cb;
solver->setIntParam(OsiNameDiscipline, 2);
solver->messageHandler()->setLogLevel(0);
solver->setHintParam(OsiDoReducePrint,true,OsiHintTry);
for(i = 0; i < p->numCols; i++)
{
solver->addCol(0, NULL, NULL, p->colLb[i], p->colUb[i], p->objCoef[i]);
solver->setColName(i, p->colName[i]);
if(p->colType[i] == CONTINUOUS)
solver->setContinuous(i);
else
solver->setInteger(i);
}
for(i = 0; i < p->numRows; i++)
{
switch(p->rowSense[i])
{
case 'E':
rowLb = p->rhs[i];
rowUb = p->rhs[i];
break;
case 'L':
rowLb = -p->infty;
rowUb = p->rhs[i];
break;
case 'G':
rowLb = p->rhs[i];
rowUb = p->infty;
break;
default:
fprintf(stderr, "Error: invalid type of constraint!\n");
exit(EXIT_FAILURE);
}
cb.addRow(p->rowNElements[i], p->idxsByRow[i], p->coefsByRow[i], rowLb, rowUb);
}
solver->addRows(cb);
for(i = 0; i < p->numRows; i++)
solver->setRowName(i, p->rowName[i]);
return solver;
}
int main (int argc, const char *argv[])
{
/* Define your favorite OsiSolver.
CbcModel clones the solver so use solver1 up to the time you pass it
to CbcModel then use a pointer to cloned solver (model.solver())
*/
OsiClpSolverInterface solver1;
/* From now on we can build model in a solver independent way.
You can add rows one at a time but for large problems this is slow so
this example uses CoinBuild or CoinModel
*/
OsiSolverInterface * solver = &solver1;
// Data (is exmip1.mps in Mps/Sample
// Objective
double objValue[]={1.0,2.0,0.0,0.0,0.0,0.0,0.0,-1.0};
// Lower bounds for columns
double columnLower[]={2.5,0.0,0.0,0.0,0.5,0.0,0.0,0.0};
// Upper bounds for columns
double columnUpper[]={COIN_DBL_MAX,4.1,1.0,1.0,4.0,
COIN_DBL_MAX,COIN_DBL_MAX,4.3};
// Lower bounds for row activities
double rowLower[]={2.5,-COIN_DBL_MAX,-COIN_DBL_MAX,1.8,3.0};
// Upper bounds for row activities
double rowUpper[]={COIN_DBL_MAX,2.1,4.0,5.0,15.0};
// Matrix stored packed
int column[] = {0,1,3,4,7,
1,2,
2,5,
3,6,
4,7};
double element[] = {3.0,1.0,-2.0,-1.0,-1.0,
2.0,1.1,
1.0,1.0,
2.8,-1.2,
1.0,1.9};
int starts[]={0,5,7,9,11,13};
// Integer variables (note upper bound already 1.0)
int whichInt[]={2,3};
int numberRows=(int) (sizeof(rowLower)/sizeof(double));
int numberColumns=(int) (sizeof(columnLower)/sizeof(double));
#define BUILD 2
#if BUILD==1
// Using CoinBuild
// First do columns (objective and bounds)
int i;
// We are not adding elements
for (i=0;i<numberColumns;i++) {
solver->addCol(0,NULL,NULL,columnLower[i],columnUpper[i],
objValue[i]);
}
// mark as integer
for (i=0;i<(int) (sizeof(whichInt)/sizeof(int));i++)
solver->setInteger(whichInt[i]);
// Now build rows
CoinBuild build;
for (i=0;i<numberRows;i++) {
int startRow = starts[i];
int numberInRow = starts[i+1]-starts[i];
build.addRow(numberInRow,column+startRow,element+startRow,
rowLower[i],rowUpper[i]);
}
// add rows into solver
solver->addRows(build);
#else
/* using CoinModel - more flexible but still beta.
Can do exactly same way but can mix and match much more.
Also all operations are on building object
*/
CoinModel build;
// First do columns (objective and bounds)
int i;
for (i=0;i<numberColumns;i++) {
build.setColumnBounds(i,columnLower[i],columnUpper[i]);
build.setObjective(i,objValue[i]);
}
// mark as integer
for (i=0;i<(int) (sizeof(whichInt)/sizeof(int));i++)
build.setInteger(whichInt[i]);
// Now build rows
for (i=0;i<numberRows;i++) {
int startRow = starts[i];
int numberInRow = starts[i+1]-starts[i];
build.addRow(numberInRow,column+startRow,element+startRow,
rowLower[i],rowUpper[i]);
}
// add rows into solver
solver->loadFromCoinModel(build);
#endif
// Pass to solver
CbcModel model(*solver);
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(3);
generator1.setMaxProbe(100);
generator1.setMaxLook(50);
generator1.setRowCuts(3);
// generator1.snapshot(*model.solver());
//generator1.createCliques(*model.solver(),2,1000,true);
//generator1.setMode(0);
CglGomory generator2;
// try larger limit
generator2.setLimit(300);
CglKnapsackCover generator3;
CglOddHole generator4;
generator4.setMinimumViolation(0.005);
generator4.setMinimumViolationPer(0.00002);
// try larger limit
generator4.setMaximumEntries(200);
CglClique generator5;
generator5.setStarCliqueReport(false);
generator5.setRowCliqueReport(false);
CglMixedIntegerRounding mixedGen;
CglFlowCover flowGen;
// Add in generators
model.addCutGenerator(&generator1,-1,"Probing");
model.addCutGenerator(&generator2,-1,"Gomory");
model.addCutGenerator(&generator3,-1,"Knapsack");
model.addCutGenerator(&generator4,-1,"OddHole");
model.addCutGenerator(&generator5,-1,"Clique");
model.addCutGenerator(&flowGen,-1,"FlowCover");
model.addCutGenerator(&mixedGen,-1,"MixedIntegerRounding");
OsiClpSolverInterface * osiclp = dynamic_cast< OsiClpSolverInterface*> (model.solver());
// go faster stripes
if (osiclp->getNumRows()<300&&osiclp->getNumCols()<500) {
osiclp->setupForRepeatedUse(2,0);
printf("trying slightly less reliable but faster version (? Gomory cuts okay?)\n");
printf("may not be safe if doing cuts in tree which need accuracy (level 2 anyway)\n");
}
// Allow rounding heuristic
CbcRounding heuristic1(model);
model.addHeuristic(&heuristic1);
// And local search when new solution found
CbcHeuristicLocal heuristic2(model);
model.addHeuristic(&heuristic2);
// Redundant definition of default branching (as Default == User)
CbcBranchUserDecision branch;
model.setBranchingMethod(&branch);
// Definition of node choice
CbcCompareUser compare;
model.setNodeComparison(compare);
// Do initial solve to continuous
model.initialSolve();
// Could tune more
model.setMinimumDrop(CoinMin(1.0,
fabs(model.getMinimizationObjValue())*1.0e-3+1.0e-4));
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(5);
// Switch off strong branching if wanted
// model.setNumberStrong(0);
// Do more strong branching if small
if (model.getNumCols()<5000)
model.setNumberStrong(10);
model.solver()->setIntParam(OsiMaxNumIterationHotStart,100);
// If time is given then stop after that number of minutes
if (argc>2) {
int minutes = atoi(argv[2]);
std::cout<<"Stopping after "<<minutes<<" minutes"<<std::endl;
assert (minutes>=0);
model.setDblParam(CbcModel::CbcMaximumSeconds,60.0*minutes);
}
// Switch off most output
if (model.getNumCols()<3000) {
model.messageHandler()->setLogLevel(1);
//model.solver()->messageHandler()->setLogLevel(0);
} else {
model.messageHandler()->setLogLevel(2);
model.solver()->messageHandler()->setLogLevel(1);
}
double time1 = CoinCpuTime();
// Do complete search
model.branchAndBound();
std::cout<<" Branch and cut 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;
int numberGenerators = model.numberCutGenerators();
for (int 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"
<<std::endl;
}
// Print solution if any - we can't get names from Osi!
if (model.getMinimizationObjValue()<1.0e50) {
int numberColumns = model.solver()->getNumCols();
const double * solution = model.solver()->getColSolution();
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&&model.solver()->isInteger(iColumn))
std::cout<<std::setw(6)<<iColumn<<" "<<value<<std::endl;
}
std::cout<<"--------------------------------------"<<std::endl;
std::cout<<std::resetiosflags(std::ios::fixed|std::ios::showpoint|std::ios::scientific);
}
return 0;
}
