Esempio n. 1
0
int main(int argc, const char *argv[])
{
     int status;
     CoinMpsIO m;
     if (argc < 2)
          status = m.readMps("model1.mps", "");
     else
          status = m.readMps(argv[1], "");

     if (status) {
          fprintf(stdout, "Bad readMps %s\n", argv[1]);
          exit(1);
     }

     // Load up model1 - so we can use known good solution
     ClpSimplex model1;
     model1.loadProblem(*m.getMatrixByCol(),
                        m.getColLower(), m.getColUpper(),
                        m.getObjCoefficients(),
                        m.getRowLower(), m.getRowUpper());
     model1.dual();
     // Get data arrays
     const CoinPackedMatrix * matrix1 = m.getMatrixByCol();
     const int * start1 = matrix1->getVectorStarts();
     const int * length1 = matrix1->getVectorLengths();
     const int * row1 = matrix1->getIndices();
     const double * element1 = matrix1->getElements();

     const double * columnLower1 = m.getColLower();
     const double * columnUpper1 = m.getColUpper();
     const double * rowLower1 = m.getRowLower();
     const double * rowUpper1 = m.getRowUpper();
     const double * objective1 = m.getObjCoefficients();

     int numberColumns = m.getNumCols();
     int numberRows = m.getNumRows();
     int numberElements = m.getNumElements();

     // Get new arrays
     int numberColumns2 = (numberColumns + 1);
     int * start2 = new int[numberColumns2+1];
     int * row2 = new int[numberElements];
     double * element2 = new double[numberElements];
     int * segstart = new int[numberColumns+1];
     double * breakpt  = new double[2*numberColumns];
     double * slope  = new double[2*numberColumns];

     double * objective2 = new double[numberColumns2];
     double * columnLower2 = new double[numberColumns2];
     double * columnUpper2 = new double[numberColumns2];
     double * rowLower2 = new double[numberRows];
     double * rowUpper2 = new double[numberRows];

     // We need to modify rhs
     memcpy(rowLower2, rowLower1, numberRows * sizeof(double));
     memcpy(rowUpper2, rowUpper1, numberRows * sizeof(double));
     double objectiveOffset = 0.0;

     // For new solution
     double * newSolution = new double [numberColumns];
     const double * oldSolution = model1.primalColumnSolution();

     int iColumn;
     for (iColumn = 0; iColumn < numberColumns; iColumn++)
          printf("%g ", oldSolution[iColumn]);
     printf("\n");

     numberColumns2 = 0;
     numberElements = 0;
     start2[0] = 0;
     int segptr = 0;

     segstart[0] = 0;

     // Now check for duplicates
     for (iColumn = 0; iColumn < numberColumns; iColumn++) {
          // test if column identical to next column
          bool ifcopy = 1;
          if (iColumn < numberColumns - 1) {
               int  joff = length1[iColumn];
               for (int j = start1[iColumn]; j < start1[iColumn] + length1[iColumn]; j++) {
                    if (row1[j] != row1[j+joff]) {
                         ifcopy = 0;
                         break;
                    }
                    if (element1[j] != element1[j+joff]) {
                         ifcopy = 0;
                         break;
                    }
               }
          } else {
               ifcopy = 0;
          }
          //if (iColumn>47||iColumn<45)
          //ifcopy=0;
          if (ifcopy) {
               double lo1 = columnLower1[iColumn];
               double up1 = columnUpper1[iColumn];
               double obj1 = objective1[iColumn];
               double sol1 = oldSolution[iColumn];
               double lo2 = columnLower1[iColumn+1];
               double up2 = columnUpper1[iColumn+1];
               double obj2 = objective1[iColumn+1];
               double sol2 = oldSolution[iColumn+1];
               if (fabs(up1 - lo2) > 1.0e-8) {
                    // try other way
                    double temp;
                    temp = lo1;
                    lo1 = lo2;
                    lo2 = temp;
                    temp = up1;
                    up1 = up2;
                    up2 = temp;
                    temp = obj1;
                    obj1 = obj2;
                    obj2 = temp;
                    temp = sol1;
                    sol1 = sol2;
                    sol2 = temp;
                    assert(fabs(up1 - lo2) < 1.0e-8);
               }
               // subtract out from rhs
               double fixed = up1;
               // do offset
               objectiveOffset += fixed * obj2;
               for (int j = start1[iColumn]; j < start1[iColumn] + length1[iColumn]; j++) {
                    int iRow = row1[j];
                    double value = element1[j];
                    if (rowLower2[iRow] > -1.0e30)
                         rowLower2[iRow] -= value * fixed;
                    if (rowUpper2[iRow] < 1.0e30)
                         rowUpper2[iRow] -= value * fixed;
               }
               newSolution[numberColumns2] = fixed;
               if (fabs(sol1 - fixed) > 1.0e-8)
                    newSolution[numberColumns2] = sol1;
               if (fabs(sol2 - fixed) > 1.0e-8)
                    newSolution[numberColumns2] = sol2;
               columnLower2[numberColumns2] = lo1;
               columnUpper2[numberColumns2] = up2;
               objective2[numberColumns2] = 0.0;
               breakpt[segptr] = lo1;
               slope[segptr++] = obj1;
               breakpt[segptr] = lo2;
               slope[segptr++] = obj2;
               for (int j = start1[iColumn]; j < start1[iColumn] + length1[iColumn]; j++) {
                    row2[numberElements] = row1[j];
                    element2[numberElements++] = element1[j];
               }
               start2[++numberColumns2] = numberElements;
               breakpt[segptr] = up2;
               slope[segptr++] = COIN_DBL_MAX;
               segstart[numberColumns2] = segptr;
               iColumn++; // skip next column
          } else {
               // normal column
               columnLower2[numberColumns2] = columnLower1[iColumn];
               columnUpper2[numberColumns2] = columnUpper1[iColumn];
               objective2[numberColumns2] = objective1[iColumn];
               breakpt[segptr] = columnLower1[iColumn];
               slope[segptr++] = objective1[iColumn];
               for (int j = start1[iColumn]; j < start1[iColumn] + length1[iColumn]; j++) {
                    row2[numberElements] = row1[j];
                    element2[numberElements++] = element1[j];
               }
               newSolution[numberColumns2] = oldSolution[iColumn];
               start2[++numberColumns2] = numberElements;
               breakpt[segptr] = columnUpper1[iColumn];
               slope[segptr++] = COIN_DBL_MAX;
               segstart[numberColumns2] = segptr;
          }
     }

     // print new number of columns, elements
     printf("New number of columns  = %d\n", numberColumns2);
     printf("New number of elements = %d\n", numberElements);
     printf("Objective offset is %g\n", objectiveOffset);


     ClpSimplex  model;

     // load up
     model.loadProblem(numberColumns2, numberRows,
                       start2, row2, element2,
                       columnLower2, columnUpper2,
                       objective2,
                       rowLower2, rowUpper2);
     model.scaling(0);
     model.setDblParam(ClpObjOffset, -objectiveOffset);
     // Create nonlinear objective
     int returnCode = model.createPiecewiseLinearCosts(segstart, breakpt, slope);
     assert(!returnCode);

     // delete
     delete [] segstart;
     delete [] breakpt;
     delete [] slope;
     delete [] start2;
     delete [] row2 ;
     delete [] element2;

     delete [] objective2;
     delete [] columnLower2;
     delete [] columnUpper2;
     delete [] rowLower2;
     delete [] rowUpper2;

     // copy in solution - (should be optimal)
     model.allSlackBasis();
     memcpy(model.primalColumnSolution(), newSolution, numberColumns2 * sizeof(double));
     //memcpy(model.columnLower(),newSolution,numberColumns2*sizeof(double));
     //memcpy(model.columnUpper(),newSolution,numberColumns2*sizeof(double));
     delete [] newSolution;
     //model.setLogLevel(63);

     const double * solution = model.primalColumnSolution();
     double * saveSol = new double[numberColumns2];
     memcpy(saveSol, solution, numberColumns2 * sizeof(double));
     for (iColumn = 0; iColumn < numberColumns2; iColumn++)
          printf("%g ", solution[iColumn]);
     printf("\n");
     // solve
     model.primal(1);
     for (iColumn = 0; iColumn < numberColumns2; iColumn++) {
          if (fabs(solution[iColumn] - saveSol[iColumn]) > 1.0e-3)
               printf(" ** was %g ", saveSol[iColumn]);
          printf("%g ", solution[iColumn]);
     }
     printf("\n");
     model.primal(1);
     for (iColumn = 0; iColumn < numberColumns2; iColumn++) {
          if (fabs(solution[iColumn] - saveSol[iColumn]) > 1.0e-3)
               printf(" ** was %g ", saveSol[iColumn]);
          printf("%g ", solution[iColumn]);
     }
     printf("\n");
     model.primal();
     for (iColumn = 0; iColumn < numberColumns2; iColumn++) {
          if (fabs(solution[iColumn] - saveSol[iColumn]) > 1.0e-3)
               printf(" ** was %g ", saveSol[iColumn]);
          printf("%g ", solution[iColumn]);
     }
     printf("\n");
     model.allSlackBasis();
     for (iColumn = 0; iColumn < numberColumns2; iColumn++) {
          if (fabs(solution[iColumn] - saveSol[iColumn]) > 1.0e-3)
               printf(" ** was %g ", saveSol[iColumn]);
          printf("%g ", solution[iColumn]);
     }
     printf("\n");
     model.setLogLevel(63);
     model.primal();
     for (iColumn = 0; iColumn < numberColumns2; iColumn++) {
          if (fabs(solution[iColumn] - saveSol[iColumn]) > 1.0e-3)
               printf(" ** was %g ", saveSol[iColumn]);
          printf("%g ", solution[iColumn]);
     }
     printf("\n");
     return 0;
}
Esempio n. 2
0
int main(int argc, const char *argv[])
{
     try {
          // Empty model
          ClpSimplex  model;

          // Objective - just nonzeros
          int objIndex[] = {0, 2};
          double objValue[] = {1.0, 4.0};
          // Upper bounds - as dense vector
          double upper[] = {2.0, COIN_DBL_MAX, 4.0};

          // Create space for 3 columns
          model.resize(0, 3);
          // Fill in
          int i;
          // Virtuous way
          // First objective
          for (i = 0; i < 2; i++)
               model.setObjectiveCoefficient(objIndex[i], objValue[i]);
          // Now bounds (lower will be zero by default but do again)
          for (i = 0; i < 3; i++) {
               model.setColumnLower(i, 0.0);
               model.setColumnUpper(i, upper[i]);
          }
          /*
            We could also have done in non-virtuous way e.g.
            double * objective = model.objective();
            and then set directly
          */
          // Faster to add rows all at once - but this is easier to show
          // Now add row 1 as >= 2.0
          int row1Index[] = {0, 2};
          double row1Value[] = {1.0, 1.0};
          model.addRow(2, row1Index, row1Value,
                       2.0, COIN_DBL_MAX);
          // Now add row 2 as == 1.0
          int row2Index[] = {0, 1, 2};
          double row2Value[] = {1.0, -5.0, 1.0};
          model.addRow(3, row2Index, row2Value,
                       1.0, 1.0);
          // solve
          model.dual();

          /*
            Adding one row at a time has a significant overhead so let's
            try a more complicated but faster way

            First time adding in 10000 rows one by one
          */
          model.allSlackBasis();
          ClpSimplex modelSave = model;
          double time1 = CoinCpuTime();
          int k;
          for (k = 0; k < 10000; k++) {
               int row2Index[] = {0, 1, 2};
               double row2Value[] = {1.0, -5.0, 1.0};
               model.addRow(3, row2Index, row2Value,
                            1.0, 1.0);
          }
          printf("Time for 10000 addRow is %g\n", CoinCpuTime() - time1);
          model.dual();
          model = modelSave;
          // Now use build
          CoinBuild buildObject;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int row2Index[] = {0, 1, 2};
               double row2Value[] = {1.0, -5.0, 1.0};
               buildObject.addRow(3, row2Index, row2Value,
                                  1.0, 1.0);
          }
          model.addRows(buildObject);
          printf("Time for 10000 addRow using CoinBuild is %g\n", CoinCpuTime() - time1);
          model.dual();
          model = modelSave;
          int del[] = {0, 1, 2};
          model.deleteRows(2, del);
          // Now use build +-1
          CoinBuild buildObject2;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int row2Index[] = {0, 1, 2};
               double row2Value[] = {1.0, -1.0, 1.0};
               buildObject2.addRow(3, row2Index, row2Value,
                                   1.0, 1.0);
          }
          model.addRows(buildObject2, true);
          printf("Time for 10000 addRow using CoinBuild+-1 is %g\n", CoinCpuTime() - time1);
          model.dual();
          model = modelSave;
          model.deleteRows(2, del);
          // Now use build +-1
          CoinModel modelObject2;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int row2Index[] = {0, 1, 2};
               double row2Value[] = {1.0, -1.0, 1.0};
               modelObject2.addRow(3, row2Index, row2Value,
                                   1.0, 1.0);
          }
          model.addRows(modelObject2, true);
          printf("Time for 10000 addRow using CoinModel+-1 is %g\n", CoinCpuTime() - time1);
          model.dual();
          model = ClpSimplex();
          // Now use build +-1
          CoinModel modelObject3;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int row2Index[] = {0, 1, 2};
               double row2Value[] = {1.0, -1.0, 1.0};
               modelObject3.addRow(3, row2Index, row2Value,
                                   1.0, 1.0);
          }
          model.loadProblem(modelObject3, true);
          printf("Time for 10000 addRow using CoinModel load +-1 is %g\n", CoinCpuTime() - time1);
          model.writeMps("xx.mps");
          model.dual();
          model = modelSave;
          // Now use model
          CoinModel modelObject;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int row2Index[] = {0, 1, 2};
               double row2Value[] = {1.0, -5.0, 1.0};
               modelObject.addRow(3, row2Index, row2Value,
                                  1.0, 1.0);
          }
          model.addRows(modelObject);
          printf("Time for 10000 addRow using CoinModel is %g\n", CoinCpuTime() - time1);
          model.dual();
          model.writeMps("b.mps");
          // Method using least memory - but most complicated
          time1 = CoinCpuTime();
          // Assumes we know exact size of model and matrix
          // Empty model
          ClpSimplex  model2;
          {
               // Create space for 3 columns and 10000 rows
               int numberRows = 10000;
               int numberColumns = 3;
               // This is fully dense - but would not normally be so
               int numberElements = numberRows * numberColumns;
               // Arrays will be set to default values
               model2.resize(numberRows, numberColumns);
               double * elements = new double [numberElements];
               CoinBigIndex * starts = new CoinBigIndex [numberColumns+1];
               int * rows = new int [numberElements];;
               int * lengths = new int[numberColumns];
               // Now fill in - totally unsafe but ....
               // no need as defaults to 0.0 double * columnLower = model2.columnLower();
               double * columnUpper = model2.columnUpper();
               double * objective = model2.objective();
               double * rowLower = model2.rowLower();
               double * rowUpper = model2.rowUpper();
               // Columns - objective was packed
               for (k = 0; k < 2; k++) {
                    int iColumn = objIndex[k];
                    objective[iColumn] = objValue[k];
               }
               for (k = 0; k < numberColumns; k++)
                    columnUpper[k] = upper[k];
               // Rows
               for (k = 0; k < numberRows; k++) {
                    rowLower[k] = 1.0;
                    rowUpper[k] = 1.0;
               }
               // Now elements
               double row2Value[] = {1.0, -5.0, 1.0};
               CoinBigIndex put = 0;
               for (k = 0; k < numberColumns; k++) {
                    starts[k] = put;
                    lengths[k] = numberRows;
                    double value = row2Value[k];
                    for (int i = 0; i < numberRows; i++) {
                         rows[put] = i;
                         elements[put] = value;
                         put++;
                    }
               }
               starts[numberColumns] = put;
               // assign to matrix
               CoinPackedMatrix * matrix = new CoinPackedMatrix(true, 0.0, 0.0);
               matrix->assignMatrix(true, numberRows, numberColumns, numberElements,
                                    elements, rows, starts, lengths);
               ClpPackedMatrix * clpMatrix = new ClpPackedMatrix(matrix);
               model2.replaceMatrix(clpMatrix, true);
               printf("Time for 10000 addRow using hand written code is %g\n", CoinCpuTime() - time1);
               // If matrix is really big could switch off creation of row copy
               // model2.setSpecialOptions(256);
          }
          model2.dual();
          model2.writeMps("a.mps");
          // Print column solution
          int numberColumns = model.numberColumns();

          // Alternatively getColSolution()
          double * columnPrimal = model.primalColumnSolution();
          // Alternatively getReducedCost()
          double * columnDual = model.dualColumnSolution();
          // Alternatively getColLower()
          double * columnLower = model.columnLower();
          // Alternatively getColUpper()
          double * columnUpper = model.columnUpper();
          // Alternatively getObjCoefficients()
          double * columnObjective = model.objective();

          int iColumn;

          std::cout << "               Primal          Dual         Lower         Upper          Cost"
                    << std::endl;

          for (iColumn = 0; iColumn < numberColumns; iColumn++) {
               double value;
               std::cout << std::setw(6) << iColumn << " ";
               value = columnPrimal[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnDual[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnLower[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnUpper[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnObjective[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << setiosflags(std::ios::scientific) << std::setw(14) << value;

               std::cout << std::endl;
          }
          std::cout << "--------------------------------------" << std::endl;
          // Test CoinAssert
          std::cout << "If Clp compiled with -g below should give assert, if with -O1 or COIN_ASSERT CoinError" << std::endl;
          model = modelSave;
          model.deleteRows(2, del);
          // Deliberate error
          model.deleteColumns(1, del + 2);
          // Now use build +-1
          CoinBuild buildObject3;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int row2Index[] = {0, 1, 2};
               double row2Value[] = {1.0, -1.0, 1.0};
               buildObject3.addRow(3, row2Index, row2Value,
                                   1.0, 1.0);
          }
          model.addRows(buildObject3, true);
     } catch (CoinError e) {
          e.print();
          if (e.lineNumber() >= 0)
               std::cout << "This was from a CoinAssert" << std::endl;
     }
     return 0;
}
Esempio n. 3
0
/*
  Randomized Rounding Heuristic
  Returns 1 if solution, 0 if not
*/
int
CbcHeuristicRandRound::solution(double & solutionValue,
                                double * betterSolution)
{
    // rlh: Todo: Memory Cleanup

    //  std::cout << "Entering the Randomized Rounding Heuristic" << std::endl;

    setWhen(1);  // setWhen(1) didn't have the effect I expected (e.g., run once).

    // Run only once.
    //
    //    See if at root node
    bool atRoot = model_->getNodeCount() == 0;
    int passNumber = model_->getCurrentPassNumber();
    //    Just do once
    if (!atRoot || passNumber > 1) {
        // std::cout << "Leaving the Randomized Rounding Heuristic" << std::endl;
        return 0;
    }

    std::cout << "Entering the Randomized Rounding Heuristic" << std::endl;
    typedef struct {
        int numberSolutions;
        int maximumSolutions;
        int numberColumns;
        double ** solution;
        int * numberUnsatisfied;
    } clpSolution;

    double start = CoinCpuTime();
    numCouldRun_++; //
#ifdef HEURISTIC_INFORM
    printf("Entering heuristic %s - nRuns %d numCould %d when %d\n",
	   heuristicName(),numRuns_,numCouldRun_,when_);
#endif
    // Todo: Ask JJHF what "number of times
    // the heuristic could run" means.

    OsiSolverInterface * solver = model_->solver()->clone();
    double primalTolerance ;
    solver->getDblParam(OsiPrimalTolerance, primalTolerance) ;
    OsiClpSolverInterface * clpSolver = dynamic_cast<OsiClpSolverInterface *> (solver);
    assert (clpSolver);
    ClpSimplex * simplex = clpSolver->getModelPtr();

    // Initialize the structure holding the solutions for the Simplex iterations
    clpSolution solutions;
    // Set typeStruct field of ClpTrustedData struct to 1 to indicate
    // desired behavior for  RandRound heuristic (which is what?)
    ClpTrustedData trustedSolutions;
    trustedSolutions.typeStruct = 1;
    trustedSolutions.data = &solutions;
    solutions.numberSolutions = 0;
    solutions.maximumSolutions = 0;
    solutions.numberColumns = simplex->numberColumns();
    solutions.solution = NULL;
    solutions.numberUnsatisfied = NULL;
    simplex->setTrustedUserPointer(&trustedSolutions);

    // Solve from all slack to get some points
    simplex->allSlackBasis();

    // Calling primal() invalidates pointers to some rim vectors,
    // like...row sense (!)
    simplex->primal();

    // 1. Okay - so a workaround would be to copy the data I want BEFORE
    // calling primal.
    // 2. Another approach is to ask the simplex solvers NOT to mess up my
    // rims.
    // 3. See freeCachedResults() for what is getting
    // deleted. Everything else points into the structure.
    // ...or use collower and colupper rather than rowsense.
    // ..store address of where one of these

    // Store the basic problem information
    // -Get the number of columns, rows and rhs vector
    int numCols = clpSolver->getNumCols();
    int numRows = clpSolver->getNumRows();

    // Find the integer variables (use columnType(?))
    // One if not continuous, that is binary or general integer)
    // columnType() = 0 continuous
    //              = 1 binary
    //              = 2 general integer
    bool * varClassInt = new bool[numCols];
    const char* columnType = clpSolver->columnType();
    int numGenInt = 0;
    for (int i = 0; i < numCols; i++) {
        if (clpSolver->isContinuous(i))
            varClassInt[i] = 0;
        else
            varClassInt[i] = 1;
        if (columnType[i] == 2) numGenInt++;
    }

    // Heuristic is for problems with general integer variables.
    // If there are none, quit.
    if (numGenInt++ < 1) {
        delete [] varClassInt ;
        std::cout << "Leaving the Randomized Rounding Heuristic" << std::endl;
        return 0;
    }


    // -Get the rows sense
    const char * rowSense;
    rowSense = clpSolver->getRowSense();

    // -Get the objective coefficients
    double *originalObjCoeff = CoinCopyOfArray(clpSolver->getObjCoefficients(), numCols);

    // -Get the matrix of the problem
    // rlh: look at using sparse representation
    double ** matrix = new double * [numRows];
    for (int i = 0; i < numRows; i++) {
        matrix[i] = new double[numCols];
        for (int j = 0; j < numCols; j++)
            matrix[i][j] = 0;
    }

    const CoinPackedMatrix* matrixByRow = clpSolver->getMatrixByRow();
    const double * matrixElements = matrixByRow->getElements();
    const int * matrixIndices = matrixByRow->getIndices();
    const int * matrixStarts = matrixByRow->getVectorStarts();
    for (int j = 0; j < numRows; j++) {
        for (int i = matrixStarts[j]; i < matrixStarts[j+1]; i++) {
            matrix[j][matrixIndices[i]] = matrixElements[i];
        }
    }

    double * newObj = new double [numCols];
    srand ( static_cast<unsigned int>(time(NULL) + 1));
    int randNum;

    // Shuffle the rows:
    // Put the rows in a random order
    // so that the optimal solution is a different corner point than the
    // starting point.
    int * index = new int [numRows];
    for (int i = 0; i < numRows; i++)
        index[i] = i;
    for (int i = 0; i < numRows; i++) {
        int temp = index[i];
        int randNumTemp = i + intRand(numRows - i);
        index[i] = index[randNumTemp];
        index[randNumTemp] = temp;
    }

    // Start finding corner points by iteratively doing the following:
    // - contruct a randomly tilted objective
    // - solve
    for (int i = 0; i < numRows; i++) {
        // TODO: that 10,000 could be a param in the member data
        if (solutions.numberSolutions  > 10000)
            break;
        randNum = intRand(2);
        for (int j = 0; j < numCols; j++) {
            // for row i and column j vary the coefficient "a bit"
            if (randNum == 1)
                // if the element is zero, then set the new obj
                // coefficient to 0.1 (i.e., round up)
                if (fabs(matrix[index[i]][j]) < primalTolerance)
                    newObj[j] = 0.1;
                else
                    // if the element is nonzero, then increase the new obj
                    // coefficient "a bit"
                    newObj[j] = matrix[index[i]][j] * 1.1;
            else
                // if randnum is 2, then
                // if the element is zero, then set the new obj coeffient
                // to NEGATIVE 0.1 (i.e., round down)
                if (fabs(matrix[index[i]][j]) < primalTolerance)
                    newObj[j] = -0.1;
                else
                    // if the element is nonzero, then DEcrease the new obj coeffienct "a bit"
                    newObj[j] = matrix[index[i]][j] * 0.9;
        }
        // Use the new "tilted" objective
        clpSolver->setObjective(newObj);

        // Based on the row sense, we decide whether to max or min
        if (rowSense[i] == 'L')
            clpSolver->setObjSense(-1);
        else
            clpSolver->setObjSense(1);

        // Solve with primal simplex
        simplex->primal(1);
        // rlh+ll: This was the original code. But we already have the
        // model pointer (it's in simplex). And, calling getModelPtr()
        // invalidates the cached data in the OsiClpSolverInterface
        // object, which means our precious rowsens is lost. So let's
        // not use the line below...
        /******* clpSolver->getModelPtr()->primal(1); */
        printf("---------------------------------------------------------------- %d\n", i);
    }
    // Iteratively do this process until...
    // either you reach the max number of corner points (aka 10K)
    // or all the rows have been used as an objective.

    // Look at solutions
    int numberSolutions = solutions.numberSolutions;
    //const char * integerInfo = simplex->integerInformation();
    //const double * columnLower = simplex->columnLower();
    //const double * columnUpper = simplex->columnUpper();
    printf("there are %d solutions\n", numberSolutions);

    // Up to here we have all the corner points
    // Now we need to do the random walks and roundings

    double ** cornerPoints = new double * [numberSolutions];
    for (int j = 0; j < numberSolutions; j++)
        cornerPoints[j] = solutions.solution[j];

    bool feasibility = 1;
    // rlh: use some COIN max instead of 1e30 (?)
    double bestObj = 1e30;
    std::vector< std::vector <double> > feasibles;
    int numFeasibles = 0;

    // Check the feasibility of the corner points
    int numCornerPoints = numberSolutions;

    const double * rhs = clpSolver->getRightHandSide();
    // rlh: row sense hasn't changed. why a fresh copy?
    // Delete next line.
    rowSense = clpSolver->getRowSense();

    for (int i = 0; i < numCornerPoints; i++) {
        //get the objective value for this this point
        double objValue = 0;
        for (int k = 0; k < numCols; k++)
            objValue += cornerPoints[i][k] * originalObjCoeff[k];

        if (objValue < bestObj) {
            // check integer feasibility
            feasibility = 1;
            for (int j = 0; j < numCols; j++) {
                if (varClassInt[j]) {
                    double closest = floor(cornerPoints[i][j] + 0.5);
                    if (fabs(cornerPoints[i][j] - closest) > primalTolerance) {
                        feasibility = 0;
                        break;
                    }
                }
            }
            // check all constraints satisfied
            if (feasibility) {
                for (int irow = 0; irow < numRows; irow++) {
                    double lhs = 0;
                    for (int j = 0; j < numCols; j++) {
                        lhs += matrix[irow][j] * cornerPoints[i][j];
                    }
                    if (rowSense[irow] == 'L' && lhs > rhs[irow] + primalTolerance) {
                        feasibility = 0;
                        break;
                    }
                    if (rowSense[irow] == 'G' && lhs < rhs[irow] - primalTolerance) {
                        feasibility = 0;
                        break;
                    }
                    if (rowSense[irow] == 'E' && (lhs - rhs[irow] > primalTolerance || lhs - rhs[irow] < -primalTolerance)) {
                        feasibility = 0;
                        break;
                    }
                }
            }

            if (feasibility) {
                numFeasibles++;
                feasibles.push_back(std::vector <double> (numCols));
                for (int k = 0; k < numCols; k++)
                    feasibles[numFeasibles-1][k] = cornerPoints[i][k];
                printf("obj: %f\n", objValue);
                if (objValue < bestObj)
                    bestObj = objValue;
            }
        }
    }
    int numFeasibleCorners;
    numFeasibleCorners = numFeasibles;
    //find the center of gravity of the corner points as the first random point
    double * rp = new double[numCols];
    for (int i = 0; i < numCols; i++) {
        rp[i] = 0;
        for (int j = 0; j < numCornerPoints; j++) {
            rp[i] += cornerPoints[j][i];
        }
        rp[i] = rp[i] / numCornerPoints;
    }

    //-------------------------------------------
    //main loop:
    // -generate the next random point
    // -round the random point
    // -check the feasibility of the random point
    //-------------------------------------------

    srand ( static_cast<unsigned int>(time(NULL) + 1));
    int numRandomPoints = 0;
    while (numRandomPoints < 50000) {
        numRandomPoints++;
        //generate the next random point
        int randomIndex = intRand(numCornerPoints);
        double random = CoinDrand48();
        for (int i = 0; i < numCols; i++) {
            rp[i] = (random * (cornerPoints[randomIndex][i] - rp[i])) + rp[i];
        }

        //CRISP ROUNDING
        //round the random point just generated
        double * roundRp = new double[numCols];
        for (int i = 0; i < numCols; i++) {
            roundRp[i] = rp[i];
            if (varClassInt[i]) {
                if (rp[i] >= 0) {
                    if (fmod(rp[i], 1) > 0.5)
                        roundRp[i] = floor(rp[i]) + 1;
                    else
                        roundRp[i] = floor(rp[i]);
                } else {
                    if (fabs(fmod(rp[i], 1)) > 0.5)
                        roundRp[i] = floor(rp[i]);
                    else
                        roundRp[i] = floor(rp[i]) + 1;

                }
            }
        }


        //SOFT ROUNDING
        // Look at original files for the "how to" on soft rounding;
        // Soft rounding omitted here.

        //Check the feasibility of the rounded random point
        // -Check the feasibility
        // -Get the rows sense
        rowSense = clpSolver->getRowSense();
        rhs = clpSolver->getRightHandSide();

        //get the objective value for this feasible point
        double objValue = 0;
        for (int i = 0; i < numCols; i++)
            objValue += roundRp[i] * originalObjCoeff[i];

        if (objValue < bestObj) {
            feasibility = 1;
            for (int i = 0; i < numRows; i++) {
                double lhs = 0;
                for (int j = 0; j < numCols; j++) {
                    lhs += matrix[i][j] * roundRp[j];
                }
                if (rowSense[i] == 'L' && lhs > rhs[i] + primalTolerance) {
                    feasibility = 0;
                    break;
                }
                if (rowSense[i] == 'G' && lhs < rhs[i] - primalTolerance) {
                    feasibility = 0;
                    break;
                }
                if (rowSense[i] == 'E' && (lhs - rhs[i] > primalTolerance || lhs - rhs[i] < -primalTolerance)) {
                    feasibility = 0;
                    break;
                }
            }
            if (feasibility) {
                printf("Feasible Found.\n");
                printf("%.2f\n", CoinCpuTime() - start);
                numFeasibles++;
                feasibles.push_back(std::vector <double> (numCols));
                for (int i = 0; i < numCols; i++)
                    feasibles[numFeasibles-1][i] = roundRp[i];
                printf("obj: %f\n", objValue);
                if (objValue < bestObj)
                    bestObj = objValue;
            }
        }
        delete [] roundRp;
    }
    printf("Number of Feasible Corners: %d\n", numFeasibleCorners);
    printf("Number of Feasibles Found: %d\n", numFeasibles);
    if (numFeasibles > 0)
        printf("Best Objective: %f\n", bestObj);
    printf("time: %.2f\n", CoinCpuTime() - start);

    if (numFeasibles == 0) {
        // cleanup
        delete [] varClassInt;
        for (int i = 0; i < numRows; i++)
            delete matrix[i];
        delete [] matrix;
        delete [] newObj;
        delete [] index;
        for (int i = 0; i < numberSolutions; i++)
            delete cornerPoints[i];
        delete [] cornerPoints;
        delete [] rp;
        return 0;
    }

    // We found something better
    solutionValue = bestObj;
    for (int k = 0; k < numCols; k++) {
        betterSolution[k] =  feasibles[numFeasibles-1][k];
    }
    delete [] varClassInt;
    for (int i = 0; i < numRows; i++)
        delete matrix[i];
    delete [] matrix;
    delete [] newObj;
    delete [] index;
    for (int i = 0; i < numberSolutions; i++)
        delete cornerPoints[i];
    delete [] cornerPoints;
    delete [] rp;
    std::cout << "Leaving the Randomized Rounding Heuristic" << std::endl;
    return 1;

}
Esempio n. 4
0
/*
  Comments needed
  Returns 1 if solution, 0 if not */
int
CbcHeuristicPivotAndFix::solution(double & /*solutionValue*/,
                                  double * /*betterSolution*/)
{

    numCouldRun_++; // Todo: Ask JJHF what this for.
    std::cout << "Entering Pivot-and-Fix Heuristic" << std::endl;

#ifdef HEURISTIC_INFORM
    printf("Entering heuristic %s - nRuns %d numCould %d when %d\n",
	   heuristicName(),numRuns_,numCouldRun_,when_);
#endif
#ifdef FORNOW
    std::cout << "Lucky you! You're in the Pivot-and-Fix Heuristic" << std::endl;
    // The struct should be moved to member data



    typedef struct {
        int numberSolutions;
        int maximumSolutions;
        int numberColumns;
        double ** solution;
        int * numberUnsatisfied;
    } clpSolution;

    double start = CoinCpuTime();

    OsiClpSolverInterface * clpSolverOriginal
    = dynamic_cast<OsiClpSolverInterface *> (model_->solver());
    assert (clpSolverOriginal);
    OsiClpSolverInterface *clpSolver(clpSolverOriginal);

    ClpSimplex * simplex = clpSolver->getModelPtr();

    // Initialize the structure holding the solutions
    clpSolution solutions;
    // Set typeStruct field of ClpTrustedData struct to one.
    // This tells Clp it's "Mahdi!"
    ClpTrustedData trustedSolutions;
    trustedSolutions.typeStruct = 1;
    trustedSolutions.data = &solutions;
    solutions.numberSolutions = 0;
    solutions.maximumSolutions = 0;
    solutions.numberColumns = simplex->numberColumns();
    solutions.solution = NULL;
    solutions.numberUnsatisfied = NULL;
    simplex->setTrustedUserPointer(&trustedSolutions);

    // Solve from all slack to get some points
    simplex->allSlackBasis();
    simplex->primal();

    // -------------------------------------------------
    // Get the problem information
    // - get the number of cols and rows
    int numCols = clpSolver->getNumCols();
    int numRows = clpSolver->getNumRows();

    // - get the right hand side of the rows
    const double * rhs = clpSolver->getRightHandSide();

    // - find the integer variables
    bool * varClassInt = new bool[numCols];
    int numInt = 0;
    for (int i = 0; i < numCols; i++) {
        if (clpSolver->isContinuous(i))
            varClassInt[i] = 0;
        else {
            varClassInt[i] = 1;
            numInt++;
        }
    }

    // -Get the rows sense
    const char * rowSense;
    rowSense = clpSolver->getRowSense();

    // -Get the objective coefficients
    const double *objCoefficients = clpSolver->getObjCoefficients();
    double *originalObjCoeff = new double [numCols];
    for (int i = 0; i < numCols; i++)
        originalObjCoeff[i] = objCoefficients[i];

    // -Get the matrix of the problem
    double ** matrix = new double * [numRows];
    for (int i = 0; i < numRows; i++) {
        matrix[i] = new double[numCols];
        for (int j = 0; j < numCols; j++)
            matrix[i][j] = 0;
    }
    const CoinPackedMatrix* matrixByRow = clpSolver->getMatrixByRow();
    const double * matrixElements = matrixByRow->getElements();
    const int * matrixIndices = matrixByRow->getIndices();
    const int * matrixStarts = matrixByRow->getVectorStarts();
    for (int j = 0; j < numRows; j++) {
        for (int i = matrixStarts[j]; i < matrixStarts[j+1]; i++) {
            matrix[j][matrixIndices[i]] = matrixElements[i];
        }
    }

    // The newObj is the randomly perturbed constraint used to find new
    // corner points
    double * newObj = new double [numCols];

    // Set the random seed
    srand ( time(NULL) + 1);
    int randNum;

    // We're going to add a new row to the LP formulation
    // after finding each new solution.
    // Adding a new row requires the new elements and the new indices.
    // The elements are original objective function coefficients.
    // The indicies are the (dense) columns indices stored in addRowIndex.
    // The rhs is the value of the new solution stored in solutionValue.
    int * addRowIndex = new int[numCols];
    for (int i = 0; i < numCols; i++)
        addRowIndex[i] = i;

    // The number of feasible solutions found by the PF heuristic.
    // This controls the return code of the solution() method.
    int numFeasibles = 0;

    // Shuffle the rows
    int * index = new int [numRows];
    for (int i = 0; i < numRows; i++)
        index[i] = i;
    for (int i = 0; i < numRows; i++) {
        int temp = index[i];
        int randNumTemp = i + (rand() % (numRows - i));
        index[i] = index[randNumTemp];
        index[randNumTemp] = temp;
    }

    // In the clpSolution struct, we store a lot of column solutions.
    // For each perturb objective, we store the solution from each
    // iteration of the LP solve.
    // For each perturb objective, we look at the collection of
    // solutions to do something extremly intelligent :-)
    // We could (and should..and will :-) wipe out the block of
    // solutions when we're done with them. But for now, we just move on
    // and store the next block of solutions for the next (perturbed)
    // objective.
    // The variable startIndex tells us where the new block begins.
    int startIndex = 0;

    // At most "fixThreshold" number of integer variables can be unsatisfied
    // for calling smallBranchAndBound().
    // The PF Heuristic only fixes fixThreshold number of variables to
    // their integer values. Not more. Not less. The reason is to give
    // the smallBB some opportunity to find better solutions. If we fix
    // everything it might be too many (leading the heuristic to come up
    // with infeasibility rather than a useful result).
    // (This is an important paramater. And it is dynamically set.)
    double fixThreshold;
    /*
        if(numInt > 400)
        fixThreshold = 17*sqrt(numInt);
        if(numInt<=400 && numInt>100)
        fixThreshold = 5*sqrt(numInt);
        if(numInt<=100)
        fixThreshold = 4*sqrt(numInt);
    */
    // Initialize fixThreshold based on the number of integer
    // variables
    if (numInt <= 100)
        fixThreshold = .35 * numInt;
    if (numInt > 100 && numInt < 1000)
        fixThreshold = .85 * numInt;
    if (numInt >= 1000)
        fixThreshold = .1 * numInt;

    // Whenever the dynamic system for changing fixThreshold
    // kicks in, it changes the parameter by the
    // fixThresholdChange amount.
    // (The 25% should be member data and tuned. Another paper!)
    double fixThresholdChange = 0.25 * fixThreshold;

    // maxNode is the maximum number of nodes we allow smallBB to
    // search. It's initialized to 400 and changed dynamically.
    // The 400 should be member data, if we become virtuous.
    int maxNode = 400;

    // We control the decision to change maxNode through the boolean
    // variable  changeMaxNode. The boolean variable is initialized to
    // true and gets set to false under a condition (and is never true
    // again.)
    // It's flipped off and stays off (in the current incarnation of PF)
    bool changeMaxNode = 1;

    // The sumReturnCode is used for the dynamic system that sets
    // fixThreshold and changeMaxNode.
    //
    // We track what's happening in sumReturnCode. There are 8 switches.
    // The first 5 switches corresponds to a return code for smallBB.
    //
    // We want to know how many times we consecutively get the same
    // return code.
    //
    // If "good" return codes are happening often enough, we're happy.
    //
    // If a "bad" returncodes happen consecutively, we want to
    // change something.
    //
    // The switch 5 is the number of times PF didn't call smallBB
    // becuase the number of integer variables that took integer values
    // was less than fixThreshold.
    //
    // The swicth 6 was added for a brilliant idea...to be announced
    // later (another paper!)
    //
    // The switch 7 is the one that changes the max node. Read the
    // code. (Todo: Verbalize the brilliant idea for the masses.)
    //
    int sumReturnCode[8];
    /*
      sumReturnCode[0] ~ -1 --> problem too big for smallBB
      sumReturnCode[1] ~ 0  --> smallBB not finshed and no soln
      sumReturnCode[2] ~ 1  --> smallBB not finshed and there is a soln
      sumReturnCode[3] ~ 2  --> smallBB finished and no soln
      sumReturnCode[4] ~ 3  --> smallBB finished and there is a soln
      sumReturnCode[5] ~ didn't call smallBranchAndBound too few to fix
      sumReturnCode[6] ~ didn't call smallBranchAndBound too many unsatisfied
      sumReturnCode[7] ~ the same as sumReturnCode[1] but becomes zero just if the returnCode is not 0
    */

    for (int i = 0; i < 8; i++)
        sumReturnCode[i] = 0;
    int * colIndex = new int[numCols];
    for (int i = 0; i < numCols; i++)
        colIndex[i] = i;
    double cutoff = COIN_DBL_MAX;
    bool didMiniBB;

    // Main loop
    for (int i = 0; i < numRows; i++) {
        // track the number of mini-bb for the dynamic threshold setting
        didMiniBB = 0;

        for (int k = startIndex; k < solutions.numberSolutions; k++)
            //if the point has 0 unsatisfied variables; make sure it is
            //feasible. Check integer feasiblity and constraints.
            if (solutions.numberUnsatisfied[k] == 0) {
                double feasibility = 1;
                //check integer feasibility
                for (int icol = 0; icol < numCols; icol++) {
                    double closest = floor(solutions.solution[k][icol] + 0.5);
                    if (varClassInt[icol] && (fabs(solutions.solution[k][icol] - closest) > 1e-6)) {
                        feasibility = 0;
                        break;
                    }
                }
                //check if the solution satisfies the constraints
                for (int irow = 0; irow < numRows; irow++) {
                    double lhs = 0;
                    for (int j = 0; j < numCols; j++)
                        lhs += matrix[irow][j] * solutions.solution[k][j];
                    if (rowSense[irow] == 'L' && lhs > rhs[irow] + 1e-6) {
                        feasibility = 0;
                        break;
                    }
                    if (rowSense[irow] == 'G' && lhs < rhs[irow] - 1e-6) {
                        feasibility = 0;
                        break;
                    }
                    if (rowSense[irow] == 'E' && (lhs - rhs[irow] > 1e-6 || lhs - rhs[irow] < -1e-6)) {
                        feasibility = 0;
                        break;
                    }
                }

                //if feasible, find the objective value and set the cutoff
                // for the smallBB and add a new constraint to the LP
                // (and update the best solution found so far for the
                // return arguments)
                if (feasibility) {
                    double objectiveValue = 0;
                    for (int j = 0; j < numCols; j++)
                        objectiveValue += solutions.solution[k][j] * originalObjCoeff[j];
                    cutoff = objectiveValue;
                    clpSolver->addRow(numCols, addRowIndex, originalObjCoeff, -COIN_DBL_MAX, cutoff);

                    // Todo: pick up the best solution in the block (not
                    // the last).
                    solutionValue = objectiveValue;
                    for (int m = 0; m < numCols; m++)
                        betterSolution[m] = solutions.solution[k][m];
                    numFeasibles++;
                }
            }

        // Go through the block of solution and decide if to call smallBB
        for (int k = startIndex; k < solutions.numberSolutions; k++) {
            if (solutions.numberUnsatisfied[k] <= fixThreshold) {
                // get new copy
                OsiSolverInterface * newSolver;
                newSolver = new OsiClpSolverInterface(*clpSolver);
                newSolver->setObjSense(1);
                newSolver->setObjective(originalObjCoeff);
                int numberColumns = newSolver->getNumCols();
                int numFixed = 0;

                // Fix the first fixThreshold number of integer vars
                // that are satisfied
                for (int iColumn = 0 ; iColumn < numberColumns ; iColumn++) {
                    if (newSolver->isInteger(iColumn)) {
                        double value = solutions.solution[k][iColumn];
                        double intValue = floor(value + 0.5);
                        if (fabs(value - intValue) < 1.0e-5) {
                            newSolver->setColLower(iColumn, intValue);
                            newSolver->setColUpper(iColumn, intValue);
                            numFixed++;
                            if (numFixed > numInt - fixThreshold)
                                break;
                        }
                    }
                }
                COIN_DETAIL_PRINT(printf("numFixed: %d\n", numFixed));
                COIN_DETAIL_PRINT(printf("fixThreshold: %f\n", fixThreshold));
		COIN_DETAIL_PRINT(printf("numInt: %d\n", numInt));
                double *newSolution = new double[numCols];
                double newSolutionValue;

                // Call smallBB on the modified problem
                int returnCode = smallBranchAndBound(newSolver, maxNode, newSolution,
                                                     newSolutionValue, cutoff, "mini");

                // If smallBB found a solution, update the better
                // solution and solutionValue (we gave smallBB our
                // cutoff, so it only finds improving solutions)
                if (returnCode == 1 || returnCode == 3) {
                    numFeasibles ++;
                    solutionValue = newSolutionValue;
                    for (int m = 0; m < numCols; m++)
                        betterSolution[m] = newSolution[m];
                    COIN_DETAIL_PRINT(printf("cutoff: %f\n", newSolutionValue));
                    COIN_DETAIL_PRINT(printf("time: %.2lf\n", CoinCpuTime() - start));
                }
                didMiniBB = 1;
                COIN_DETAIL_PRINT(printf("returnCode: %d\n", returnCode));

                //Update sumReturnCode array
                for (int iRC = 0; iRC < 6; iRC++) {
                    if (iRC == returnCode + 1)
                        sumReturnCode[iRC]++;
                    else
                        sumReturnCode[iRC] = 0;
                }
                if (returnCode != 0)
                    sumReturnCode[7] = 0;
                else
                    sumReturnCode[7]++;
                if (returnCode == 1 || returnCode == 3) {
                    cutoff = newSolutionValue;
                    clpSolver->addRow(numCols, addRowIndex, originalObjCoeff, -COIN_DBL_MAX, cutoff);
                    COIN_DETAIL_PRINT(printf("******************\n\n*****************\n"));
                }
                break;
            }
        }

        if (!didMiniBB && solutions.numberSolutions - startIndex > 0) {
            sumReturnCode[5]++;
            for (int iRC = 0; iRC < 5; iRC++)
                sumReturnCode[iRC] = 0;
        }

        //Change "fixThreshold" if needed
        // using the data we've recorded in sumReturnCode
        if (sumReturnCode[1] >= 3)
            fixThreshold -= fixThresholdChange;
        if (sumReturnCode[7] >= 3 && changeMaxNode) {
            maxNode *= 5;
            changeMaxNode = 0;
        }
        if (sumReturnCode[3] >= 3 && fixThreshold < 0.95 * numInt)
            fixThreshold += fixThresholdChange;
        if (sumReturnCode[5] >= 4)
            fixThreshold += fixThresholdChange;
        if (sumReturnCode[0] > 3)
            fixThreshold -= fixThresholdChange;

        startIndex = solutions.numberSolutions;

        //Check if the maximum iterations limit is reached
        // rlh: Ask John how this is working with the change to trustedUserPtr.
        if (solutions.numberSolutions > 20000)
            break;

        // The first time in this loop PF solves orig LP.

        //Generate the random objective function
        randNum = rand() % 10 + 1;
        randNum = fmod(randNum, 2);
        for (int j = 0; j < numCols; j++) {
            if (randNum == 1)
                if (fabs(matrix[index[i]][j]) < 1e-6)
                    newObj[j] = 0.1;
                else
                    newObj[j] = matrix[index[i]][j] * 1.1;
            else if (fabs(matrix[index[i]][j]) < 1e-6)
                newObj[j] = -0.1;
            else
                newObj[j] = matrix[index[i]][j] * 0.9;
        }
        clpSolver->setObjective(newObj);
        if (rowSense[i] == 'L')
            clpSolver->setObjSense(-1);
        else
            // Todo #1: We don't need to solve the LPs to optimality.
            // We just need corner points.
            // There's a problem in stopping Clp that needs to be looked
            // into. So for now, we solve optimality.
            clpSolver->setObjSense(1);
        //	  simplex->setMaximumIterations(100);
        clpSolver->getModelPtr()->primal(1);
        //	  simplex->setMaximumIterations(100000);
#ifdef COIN_DETAIL
        printf("cutoff: %f\n", cutoff);
        printf("time: %.2f\n", CoinCpuTime() - start);
        for (int iRC = 0; iRC < 8; iRC++)
            printf("%d ", sumReturnCode[iRC]);
        printf("\nfixThreshold: %f\n", fixThreshold);
        printf("numInt: %d\n", numInt);
        printf("\n---------------------------------------------------------------- %d\n", i);
#endif

        //temp:
        if (i > 3) break;

    }

    COIN_DETAIL_PRINT(printf("Best Feasible Found: %f\n", cutoff));
    COIN_DETAIL_PRINT(printf("Total time: %.2f\n", CoinCpuTime() - start));

    if (numFeasibles == 0) {
        return 0;
    }



    // We found something better
    std::cout << "See you soon! You're leaving the Pivot-and-Fix Heuristic" << std::endl;
    std::cout << std::endl;

    return 1;
#endif

    return 0;

}
Esempio n. 5
0
int main(int argc, const char *argv[])
{
     {
          // Empty model
          ClpSimplex  model;

          // Bounds on rows - as dense vector
          double lower[] = {2.0, 1.0};
          double upper[] = {COIN_DBL_MAX, 1.0};

          // Create space for 2 rows
          model.resize(2, 0);
          // Fill in
          int i;
          // Now row bounds
          for (i = 0; i < 2; i++) {
               model.setRowLower(i, lower[i]);
               model.setRowUpper(i, upper[i]);
          }
          // Now add column 1
          int column1Index[] = {0, 1};
          double column1Value[] = {1.0, 1.0};
          model.addColumn(2, column1Index, column1Value,
                          0.0, 2, 1.0);
          // Now add column 2
          int column2Index[] = {1};
          double column2Value[] = { -5.0};
          model.addColumn(1, column2Index, column2Value,
                          0.0, COIN_DBL_MAX, 0.0);
          // Now add column 3
          int column3Index[] = {0, 1};
          double column3Value[] = {1.0, 1.0};
          model.addColumn(2, column3Index, column3Value,
                          0.0, 4.0, 4.0);
          // solve
          model.dual();

          /*
            Adding one column at a time has a significant overhead so let's
            try a more complicated but faster way

            First time adding in 10000 columns one by one

          */
          model.allSlackBasis();
          ClpSimplex modelSave = model;
          double time1 = CoinCpuTime();
          int k;
          for (k = 0; k < 10000; k++) {
               int column2Index[] = {0, 1};
               double column2Value[] = {1.0, -5.0};
               model.addColumn(2, column2Index, column2Value,
                               0.0, 1.0, 10000.0);
          }
          printf("Time for 10000 addColumn is %g\n", CoinCpuTime() - time1);
          model.dual();
          model = modelSave;
          // Now use build
          CoinBuild buildObject;
          time1 = CoinCpuTime();
          for (k = 0; k < 100000; k++) {
               int column2Index[] = {0, 1};
               double column2Value[] = {1.0, -5.0};
               buildObject.addColumn(2, column2Index, column2Value,
                                     0.0, 1.0, 10000.0);
          }
          model.addColumns(buildObject);
          printf("Time for 100000 addColumn using CoinBuild is %g\n", CoinCpuTime() - time1);
          model.dual();
          model = modelSave;
          // Now use build +-1
          int del[] = {0, 1, 2};
          model.deleteColumns(3, del);
          CoinBuild buildObject2;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int column2Index[] = {0, 1};
               double column2Value[] = {1.0, 1.0, -1.0};
               int bias = k & 1;
               buildObject2.addColumn(2, column2Index, column2Value + bias,
                                      0.0, 1.0, 10000.0);
          }
          model.addColumns(buildObject2, true);
          printf("Time for 10000 addColumn using CoinBuild+-1 is %g\n", CoinCpuTime() - time1);
          model.dual();
          model = modelSave;
          // Now use build +-1
          model.deleteColumns(3, del);
          CoinModel modelObject2;
          time1 = CoinCpuTime();
          for (k = 0; k < 10000; k++) {
               int column2Index[] = {0, 1};
               double column2Value[] = {1.0, 1.0, -1.0};
               int bias = k & 1;
               modelObject2.addColumn(2, column2Index, column2Value + bias,
                                      0.0, 1.0, 10000.0);
          }
          model.addColumns(modelObject2, true);
          printf("Time for 10000 addColumn using CoinModel+-1 is %g\n", CoinCpuTime() - time1);
          //model.writeMps("xx.mps");
          model.dual();
          model = modelSave;
          // Now use model
          CoinModel modelObject;
          time1 = CoinCpuTime();
          for (k = 0; k < 100000; k++) {
               int column2Index[] = {0, 1};
               double column2Value[] = {1.0, -5.0};
               modelObject.addColumn(2, column2Index, column2Value,
                                     0.0, 1.0, 10000.0);
          }
          model.addColumns(modelObject);
          printf("Time for 100000 addColumn using CoinModel is %g\n", CoinCpuTime() - time1);
          model.dual();
          // Print column solution Just first 3 columns
          int numberColumns = model.numberColumns();
          numberColumns = CoinMin(3, numberColumns);

          // Alternatively getColSolution()
          double * columnPrimal = model.primalColumnSolution();
          // Alternatively getReducedCost()
          double * columnDual = model.dualColumnSolution();
          // Alternatively getColLower()
          double * columnLower = model.columnLower();  // Alternatively getColUpper()
          double * columnUpper = model.columnUpper();
          // Alternatively getObjCoefficients()
          double * columnObjective = model.objective();

          int iColumn;

          std::cout << "               Primal          Dual         Lower         Upper          Cost"
                    << std::endl;

          for (iColumn = 0; iColumn < numberColumns; iColumn++) {
               double value;
               std::cout << std::setw(6) << iColumn << " ";
               value = columnPrimal[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << std::setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << std::setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnDual[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << std::setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << std::setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnLower[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << std::setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << std::setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnUpper[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << std::setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << std::setiosflags(std::ios::scientific) << std::setw(14) << value;
               value = columnObjective[iColumn];
               if (fabs(value) < 1.0e5)
                    std::cout << std::setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14) << value;
               else
                    std::cout << std::setiosflags(std::ios::scientific) << std::setw(14) << value;

               std::cout << std::endl;
          }
          std::cout << "--------------------------------------" << std::endl;
     }
     {
          // Now copy a model
          ClpSimplex  model;
          int status;
          if (argc < 2) {
#if defined(SAMPLEDIR)
               status = model.readMps(SAMPLEDIR "/p0033.mps", true);
#else
               fprintf(stderr, "Do not know where to find sample MPS files.\n");
               exit(1);
#endif
          } else
               status = model.readMps(argv[1]);
          if (status) {
               printf("errors on input\n");
               exit(77);
          }
          model.initialSolve();
          int numberRows = model.numberRows();
          int numberColumns = model.numberColumns();
          const double * rowLower = model.rowLower();
          const double * rowUpper = model.rowUpper();

          // Start off model2
          ClpSimplex model2;
          model2.addRows(numberRows, rowLower, rowUpper, NULL);

          // Build object
          CoinBuild buildObject;
          // Add columns
          const double * columnLower = model.columnLower();
          const double * columnUpper = model.columnUpper();
          const double * objective = model.objective();
          CoinPackedMatrix * matrix = model.matrix();
          const int * row = matrix->getIndices();
          const int * columnLength = matrix->getVectorLengths();
          const CoinBigIndex * columnStart = matrix->getVectorStarts();
          const double * elementByColumn = matrix->getElements();
          for (int iColumn = 0; iColumn < numberColumns; iColumn++) {
               CoinBigIndex start = columnStart[iColumn];
               buildObject.addColumn(columnLength[iColumn], row + start, elementByColumn + start,
                                     columnLower[iColumn], columnUpper[iColumn],
                                     objective[iColumn]);
          }

          // add in
          model2.addColumns(buildObject);
          model2.initialSolve();
     }
     {
          // and again
          ClpSimplex  model;
          int status;
          if (argc < 2) {
#if defined(SAMPLEDIR)
               status = model.readMps(SAMPLEDIR "/p0033.mps", true);
#else
               fprintf(stderr, "Do not know where to find sample MPS files.\n");
               exit(1);
#endif
          } else
               status = model.readMps(argv[1]);
          if (status) {
               printf("errors on input\n");
               exit(77);
          }
          model.initialSolve();
          int numberRows = model.numberRows();
          int numberColumns = model.numberColumns();
          const double * rowLower = model.rowLower();
          const double * rowUpper = model.rowUpper();

          // Build object
          CoinModel buildObject;
          for (int iRow = 0; iRow < numberRows; iRow++)
               buildObject.setRowBounds(iRow, rowLower[iRow], rowUpper[iRow]);

          // Add columns
          const double * columnLower = model.columnLower();
          const double * columnUpper = model.columnUpper();
          const double * objective = model.objective();
          CoinPackedMatrix * matrix = model.matrix();
          const int * row = matrix->getIndices();
          const int * columnLength = matrix->getVectorLengths();
          const CoinBigIndex * columnStart = matrix->getVectorStarts();
          const double * elementByColumn = matrix->getElements();
          for (int iColumn = 0; iColumn < numberColumns; iColumn++) {
               CoinBigIndex start = columnStart[iColumn];
               buildObject.addColumn(columnLength[iColumn], row + start, elementByColumn + start,
                                     columnLower[iColumn], columnUpper[iColumn],
                                     objective[iColumn]);
          }

          // add in
          ClpSimplex model2;
          model2.loadProblem(buildObject);
          model2.initialSolve();
     }
     return 0;
}
Esempio n. 6
0
int main(int argc, const char *argv[])
{
     ClpSimplex  model;
     int status;

     if (argc < 2) {
#if defined(SAMPLEDIR)
          status = model.readMps(SAMPLEDIR "/p0033.mps", true);
#else
          fprintf(stderr, "Do not know where to find sample MPS files.\n");
          exit(1);
#endif
     } else
          status = model.readMps(argv[1], true);
     if( status != 0 )
     {
        printf("Error %d reading MPS file\n", status);
        return status;
     }
     /*
       This driver uses volume algorithm
       then does dual - after adjusting costs
       then solves real problem
     */

     // do volume for a bit
     VOL_problem volprob;
     const CoinPackedMatrix* mat = model.matrix();
     const int psize = mat->getNumCols();
     const int dsize = mat->getNumRows();
     char * sense = new char[dsize];
     double * rhs = new double[dsize];
     const double * rowLower = model.rowLower();
     const double * rowUpper = model.rowUpper();
     // Set the lb/ub on the duals
     volprob.dsize = dsize;
     volprob.psize = psize;
     volprob.dual_lb.allocate(dsize);
     volprob.dual_ub.allocate(dsize);
     volprob.dsol.allocate(dsize);
     int i;
     for (i = 0; i < dsize; ++i) {
          if (rowUpper[i] == rowLower[i]) {
               // 'E':
               volprob.dual_lb[i] = -1.0e31;
               volprob.dual_ub[i] = 1.0e31;
               rhs[i] = rowUpper[i];
               sense[i] = 'E';
          } else if (rowLower[i] < -0.99e10 && rowUpper[i] < 0.99e10) {
               // 'L':
               volprob.dual_lb[i] = -1.0e31;
               volprob.dual_ub[i] = 0.0;
               rhs[i] = rowUpper[i];
               sense[i] = 'L';
          } else if (rowLower[i] > -0.99e10 && rowUpper[i] > 0.99e10) {
               // 'G':
               volprob.dual_lb[i] = 0.0;
               volprob.dual_ub[i] = 1.0e31;
               rhs[i] = rowLower[i];
               sense[i] = 'G';
          } else {
               printf("Volume Algorithm can't work if there is a non ELG row\n");
               abort();
          }
     }
     // Can't use read_param as private
     // anyway I want automatic use - so maybe this is problem
#if 0
     FILE* infile = fopen("parameters", "r");
     if (!infile) {
          printf("Failure to open parameter file\n");
     } else {
          volprob.read_params("parameters");
     }
#endif
#if 0
     // should save and restore bounds
     model.tightenPrimalBounds();
#else
     double * colUpper = model.columnUpper();
     for (i = 0; i < psize; i++)
          colUpper[i] = 1.0;
#endif
     lpHook myHook(model.getColLower(), model.getColUpper(),
                   model.getObjCoefficients(),
                   rhs, sense, *mat);
     // move duals
     double * pi = model.dualRowSolution();
     memcpy(volprob.dsol.v, pi, dsize * sizeof(double));
     volprob.solve(myHook,  false /* not warmstart */);
     // For now stop as not doing any good
     exit(77);
     // create objectives
     int numberRows = model.numberRows();
     int numberColumns = model.numberColumns();
     memcpy(pi, volprob.dsol.v, numberRows * sizeof(double));
#define MODIFYCOSTS
#ifdef MODIFYCOSTS
     double * saveObj = new double[numberColumns];
     memcpy(saveObj, model.objective(), numberColumns * sizeof(double));
     memcpy(model.dualColumnSolution(), model.objective(),
            numberColumns * sizeof(double));
     model.clpMatrix()->transposeTimes(-1.0, pi, model.dualColumnSolution());
     memcpy(model.objective(), model.dualColumnSolution(),
            numberColumns * sizeof(double));
     const double * rowsol = model.primalRowSolution();
     //const double * rowLower = model.rowLower();
     //const double * rowUpper = model.rowUpper();
     double offset = 0.0;
     for (i = 0; i < numberRows; i++) {
          offset += pi[i] * rowsol[i];
     }
     double value2;
     model.getDblParam(ClpObjOffset, value2);
     printf("Offset %g %g\n", offset, value2);
     model.setRowObjective(pi);
     // zero out pi
     memset(pi, 0, numberRows * sizeof(double));
#endif
     // Could put some in basis - only partially tested
     model.allSlackBasis();
     model.factorization()->maximumPivots(1000);
     //model.setLogLevel(63);
     // solve
     model.dual(1);
     //model.primal(1);
#ifdef MODIFYCOSTS
     memcpy(model.objective(), saveObj, numberColumns * sizeof(double));
     // zero out pi
     memset(pi, 0, numberRows * sizeof(double));
     model.setRowObjective(pi);
     delete [] saveObj;
     model.primal();
#endif

     return 0;
}