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/* $Id: rowColumn.cpp 1559 2010-06-05 19:42:36Z stefan $ */
/* Copyright (C) 2004, International Business Machines Corporation
and others. All Rights Reserved.
This sample program is designed to illustrate programming
techniques using CoinLP, has not been thoroughly tested
and comes without any warranty whatsoever.
You may copy, modify and distribute this sample program without
any restrictions whatsoever and without any payment to anyone.
*/
#include "ClpSimplex.hpp"
#include <cstdio>
#include <cassert>
int main(int argc, const char *argv[])
{
ClpSimplex modelByRow, modelByColumn;
// This very simple example shows how to create a model by row and by column
int numberRows = 3;
int numberColumns = 5;
// Rim of problem is same in both cases
double objective [] = {1000.0, 400.0, 500.0, 10000.0, 10000.0};
double columnLower[] = {0.0, 0.0, 0.0, 0.0, 0.0};
double columnUpper[] = {COIN_DBL_MAX, COIN_DBL_MAX, COIN_DBL_MAX, 20.0, 20.0};
double rowLower[] = {20.0, -COIN_DBL_MAX, 8.0};
double rowUpper[] = {COIN_DBL_MAX, 30.0, 8.0};
// Matrix by row
int rowStart[] = {0, 5, 10, 13};
int column[] = {0, 1, 2, 3, 4,
0, 1, 2, 3, 4,
0, 1, 2
};
double elementByRow[] = {8.0, 5.0, 4.0, 4.0, -4.0,
8.0, 4.0, 5.0, 5.0, -5.0,
1.0, -1.0, -1.0
};
// Matrix by column
int columnStart[] = {0, 3, 6, 9, 11, 13};
int row[] = {0, 1, 2,
0, 1, 2,
0, 1, 2,
0, 1,
0, 1
};
double elementByColumn[] = {8.0, 8.0, 1.0,
5.0, 4.0, -1.0,
4.0, 5.0, -1.0,
4.0, 5.0,
-4.0, -5.0
};
int numberElements;
// Do column version first as it can be done two ways
// a) As one step using matrix as stored
modelByColumn.loadProblem(numberColumns, numberRows, columnStart, row, elementByColumn,
columnLower, columnUpper, objective,
rowLower, rowUpper);
// Solve
modelByColumn.dual();
// check value of objective
assert(fabs(modelByColumn.objectiveValue() - 76000.0) < 1.0e-7);
// b) As two steps - first creating a CoinPackedMatrix
// NULL for column lengths indicate they are stored without gaps
// Look at CoinPackedMatrix.hpp for other ways to create a matrix
numberElements = columnStart[numberColumns];
CoinPackedMatrix byColumn(true, numberRows, numberColumns, numberElements,
elementByColumn, row, columnStart, NULL);
// now load matrix and rim
modelByColumn.loadProblem(byColumn,
columnLower, columnUpper, objective,
rowLower, rowUpper);
// Solve
modelByColumn.dual();
// check value of objective
assert(fabs(modelByColumn.objectiveValue() - 76000.0) < 1.0e-7);
// Now do by row
// The false says row ordered so numberRows and numberColumns swapped - see CoinPackedMatrix.hpp
assert(numberElements == rowStart[numberRows]); // check same number of elements in each copy
CoinPackedMatrix byRow(false, numberColumns, numberRows, numberElements,
elementByRow, column, rowStart, NULL);
// now load matrix and rim
modelByRow.loadProblem(byRow,
columnLower, columnUpper, objective,
rowLower, rowUpper);
// Solve
modelByRow.dual();
// check value of objective
assert(fabs(modelByRow.objectiveValue() - 76000.0) < 1.0e-7);
// write solution
const double * solution = modelByRow.primalColumnSolution();
for (int i = 0; i < numberColumns; i++) {
if (solution[i])
printf("Column %d has value %g\n",
i, solution[i]);
}
modelByRow.writeMps("Tiny.mps");
return 0;
}
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