source: trunk/Cbc/examples/modify.cpp

Last change on this file was 1854, checked in by stefan, 6 years ago

fix svn keywords property

  • Property svn:keywords set to Author Date Id Revision
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1// $Id: modify.cpp 1854 2013-01-28 00:02:55Z forrest $
2// Copyright (C) 2007, International Business Machines
3// Corporation and others.  All Rights Reserved.
4// This code is licensed under the terms of the Eclipse Public License (EPL).
5
6/*
7  This example shows the creation of a model from arrays, solution
8  and then changes to objective and adding a row
9*/
10
11#include "CbcModel.hpp"
12
13// Using as solver
14#include "OsiClpSolverInterface.hpp"
15
16int main (int argc, const char *argv[])
17{
18  // model is as exmip1.mps from Data/samples
19  int numberRows=5;
20  int numberColumns=8;
21  int numberElements=14;
22  // matrix data - column ordered
23  CoinBigIndex start[9]={0,2,4,6,8,10,11,12,14};
24  int length[8]={2,2,2,2,2,1,1,2};
25  int rows[14]={0,4,0,1,1,2,0,3,0,4,2,3,0,4};
26  double elements[14]={3,5.6,1,2,1.1,1,-2,2.8,-1,1,1,-1.2,-1,1.9};
27  CoinPackedMatrix matrix(true,numberRows,numberColumns,numberElements,elements,rows,start,length);
28   
29  // rim data
30  double objective[8]={1,0,0,0,2,0,0,-1};
31  double rowLower[5]={2.5,-COIN_DBL_MAX,4,1.8,3};
32  double rowUpper[5]={COIN_DBL_MAX,2.1,4,5,15};
33  double colLower[8]={2.5,0,0,0,0.5,0,0,0};
34  double colUpper[8]={COIN_DBL_MAX,4.1,1,1,4,COIN_DBL_MAX,COIN_DBL_MAX,4.3};
35  OsiClpSolverInterface solver1;
36  // load problem
37  solver1.loadProblem(matrix,colLower,colUpper,objective,
38                         rowLower,rowUpper);
39  // mark integer
40  solver1.setInteger(2);
41  solver1.setInteger(3);
42
43  // Solve
44  solver1.initialSolve();
45
46  // Pass data and solver to CbcModel
47  CbcModel model(solver1);
48
49  // reduce printout
50  model.setLogLevel(1);
51  model.solver()->setHintParam(OsiDoReducePrint,true,OsiHintTry);
52  // Do complete search
53  model.branchAndBound();
54  /* Print solution.  CbcModel clones solver so we
55     need to get current copy */
56   
57  const double * solution = model.solver()->getColSolution();
58  int i;
59   
60  for (i=0;i<numberColumns;i++) {
61    double value=solution[i];
62    if (fabs(value)>1.0e-7&&model.solver()->isInteger(i)) 
63      printf("i %d has value %g\n",i,value);
64    else if (fabs(value)>1.0e-7) 
65      printf("c %d has value %g\n",i,value);
66  }
67
68  // Change objective
69  solver1.setObjCoeff(0,-100.0);
70
71  // Now model has too much information e.g. best solution
72  // simplest is to start again
73  // Pass data and solver to CbcModel
74  model = CbcModel(solver1);
75
76  // reduce printout
77  model.setLogLevel(1);
78  model.solver()->setHintParam(OsiDoReducePrint,true,OsiHintTry);
79  // Do complete search
80  model.branchAndBound();
81
82  solution = model.solver()->getColSolution();
83   
84  for (i=0;i<numberColumns;i++) {
85    double value=solution[i];
86    if (fabs(value)>1.0e-7&&model.solver()->isInteger(i)) 
87      printf("i %d has value %g\n",i,value);
88    else if (fabs(value)>1.0e-7) 
89      printf("c %d has value %g\n",i,value);
90  }
91
92  // Add constraint
93  int column[8]={0,1,2,3,4,5,6,7};
94  double element2[8] ={1,1,1,1,1,1,1,1};
95  solver1.addRow(8,column,element2,7.8,COIN_DBL_MAX);
96
97  // Now model has too much information e.g. best solution
98  // simplest is to start again
99  // Pass data and solver to CbcModel
100  model = CbcModel(solver1);
101
102  // reduce printout
103  model.setLogLevel(1);
104  model.solver()->setHintParam(OsiDoReducePrint,true,OsiHintTry);
105  // Do complete search
106  model.branchAndBound();
107
108  solution = model.solver()->getColSolution();
109   
110  for (i=0;i<numberColumns;i++) {
111    double value=solution[i];
112    if (fabs(value)>1.0e-7&&model.solver()->isInteger(i)) 
113      printf("i %d has value %g\n",i,value);
114    else if (fabs(value)>1.0e-7) 
115      printf("c %d has value %g\n",i,value);
116  }
117  return 0;
118}   
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