1 | /* Copyright (C) 2004, International Business Machines Corporation |
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2 | and others. All Rights Reserved. |
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3 | |
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4 | This sample program is designed to illustrate programming |
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5 | techniques using CoinLP, has not been thoroughly tested |
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6 | and comes without any warranty whatsoever. |
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7 | |
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8 | You may copy, modify and distribute this sample program without |
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9 | any restrictions whatsoever and without any payment to anyone. |
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10 | */ |
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11 | |
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12 | #include "ClpSimplex.hpp" |
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13 | #include <cstdio> |
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14 | #include <cassert> |
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15 | |
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16 | int main (int argc, const char *argv[]) |
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17 | { |
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18 | ClpSimplex modelByRow, modelByColumn; |
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19 | |
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20 | // This very simple example shows how to create a model by row and by column |
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21 | int numberRows=3; |
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22 | int numberColumns=5; |
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23 | // Rim of problem is same in both cases |
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24 | double objective [] = {1000.0,400.0,500.0,10000.0,10000.0}; |
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25 | double columnLower[] = {0.0,0.0,0.0,0.0,0.0}; |
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26 | double columnUpper[] = {COIN_DBL_MAX,COIN_DBL_MAX,COIN_DBL_MAX,20.0,20.0}; |
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27 | double rowLower[] = {20.0,-COIN_DBL_MAX,8.0}; |
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28 | double rowUpper[] = {COIN_DBL_MAX,30.0,8.0}; |
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29 | // Matrix by row |
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30 | int rowStart[] = {0,5,10,13}; |
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31 | int column[] = {0,1,2,3,4, |
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32 | 0,1,2,3,4, |
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33 | 0,1,2}; |
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34 | double elementByRow[] = {8.0,5.0,4.0,4.0,-4.0, |
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35 | 8.0,4.0,5.0,5.0,-5.0, |
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36 | 1.0,-1.0,-1.0}; |
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37 | // Matrix by column |
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38 | int columnStart[] = {0,3,6,9,11,13}; |
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39 | int row[] = {0,1,2, |
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40 | 0,1,2, |
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41 | 0,1,2, |
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42 | 0,1, |
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43 | 0,1}; |
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44 | double elementByColumn[] = {8.0,8.0,1.0, |
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45 | 5.0,4.0,-1.0, |
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46 | 4.0,5.0,-1.0, |
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47 | 4.0,5.0, |
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48 | -4.0,-5.0}; |
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49 | int numberElements; |
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50 | // Do column version first as it can be done two ways |
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51 | // a) As one step using matrix as stored |
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52 | modelByColumn.loadProblem(numberColumns,numberRows,columnStart,row,elementByColumn, |
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53 | columnLower,columnUpper,objective, |
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54 | rowLower,rowUpper); |
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55 | // Solve |
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56 | modelByColumn.dual(); |
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57 | // check value of objective |
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58 | assert (fabs(modelByColumn.objectiveValue()-76000.0)<1.0e-7); |
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59 | // b) As two steps - first creating a CoinPackedMatrix |
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60 | // NULL for column lengths indicate they are stored without gaps |
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61 | // Look at CoinPackedMatrix.hpp for other ways to create a matrix |
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62 | numberElements = columnStart[numberColumns]; |
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63 | CoinPackedMatrix byColumn(true,numberRows,numberColumns,numberElements, |
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64 | elementByColumn,row,columnStart,NULL); |
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65 | // now load matrix and rim |
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66 | modelByColumn.loadProblem(byColumn, |
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67 | columnLower,columnUpper,objective, |
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68 | rowLower,rowUpper); |
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69 | // Solve |
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70 | modelByColumn.dual(); |
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71 | // check value of objective |
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72 | assert (fabs(modelByColumn.objectiveValue()-76000.0)<1.0e-7); |
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73 | // Now do by row |
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74 | // The false says row ordered so numberRows and numberColumns swapped - see CoinPackedMatrix.hpp |
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75 | assert(numberElements == rowStart[numberRows]); // check same number of elements in each copy |
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76 | CoinPackedMatrix byRow(false,numberColumns,numberRows,numberElements, |
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77 | elementByRow,column,rowStart,NULL); |
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78 | // now load matrix and rim |
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79 | modelByRow.loadProblem(byRow, |
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80 | columnLower,columnUpper,objective, |
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81 | rowLower,rowUpper); |
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82 | // Solve |
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83 | modelByRow.dual(); |
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84 | // check value of objective |
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85 | assert (fabs(modelByRow.objectiveValue()-76000.0)<1.0e-7); |
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86 | // write solution |
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87 | const double * solution = modelByRow.primalColumnSolution(); |
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88 | for (int i=0;i<numberColumns;i++) { |
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89 | if (solution[i]) |
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90 | printf("Column %d has value %g\n", |
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91 | i,solution[i]); |
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92 | } |
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93 | modelByRow.writeMps("Tiny.mps"); |
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94 | return 0; |
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95 | } |
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