COIN-OR::LEMON - Graph Library

source: lemon/test/mip_test.cc @ 485:9b082b3fb33f

Last change on this file since 485:9b082b3fb33f was 485:9b082b3fb33f, checked in by Alpar Juttner <alpar@…>, 10 years ago

Rename Lp*/Mip* to *Lp/*Mip

File size: 2.6 KB
Line 
1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2008
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19#include "test_tools.h"
20
21
22#ifdef HAVE_CONFIG_H
23#include <lemon/config.h>
24#endif
25
26#ifdef HAVE_CPLEX
27#include <lemon/cplex.h>
28#endif
29
30#ifdef HAVE_GLPK
31#include <lemon/glpk.h>
32#endif
33
34
35using namespace lemon;
36
37void solveAndCheck(MipSolver& mip, MipSolver::ProblemType stat,
38                   double exp_opt) {
39  using std::string;
40
41  mip.solve();
42  //int decimal,sign;
43  std::ostringstream buf;
44  buf << "Type should be: " << int(stat)<<" and it is "<<int(mip.type());
45
46
47  //  itoa(stat,buf1, 10);
48  check(mip.type()==stat, buf.str());
49
50  if (stat ==  MipSolver::OPTIMAL) {
51    std::ostringstream sbuf;
52    buf << "Wrong optimal value: the right optimum is " << exp_opt;
53    check(std::abs(mip.solValue()-exp_opt) < 1e-3, sbuf.str());
54    //+ecvt(exp_opt,2)
55  }
56}
57
58void aTest(MipSolver& mip)
59{
60 //The following example is very simple
61
62
63  typedef MipSolver::Row Row;
64  typedef MipSolver::Col Col;
65
66
67
68  Col x1 = mip.addCol();
69  Col x2 = mip.addCol();
70
71
72  //Objective function
73  mip.obj(x1);
74
75  mip.max();
76
77
78  //Unconstrained optimization
79  mip.solve();
80  //Check it out!
81
82  //Constraints
83  mip.addRow(2*x1+x2 <=2);
84  mip.addRow(x1-2*x2 <=0);
85
86  //Nonnegativity of the variable x1
87  mip.colLowerBound(x1, 0);
88
89  //Maximization of x1
90  //over the triangle with vertices (0,0),(4/5,2/5),(0,2)
91  double expected_opt=4.0/5.0;
92  solveAndCheck(mip, MipSolver::OPTIMAL, expected_opt);
93
94  //Restrict x2 to integer
95  mip.colType(x2,MipSolver::INTEGER);
96  expected_opt=1.0/2.0;
97  solveAndCheck(mip, MipSolver::OPTIMAL, expected_opt);
98
99
100  //Restrict both to integer
101  mip.colType(x1,MipSolver::INTEGER);
102  expected_opt=0;
103  solveAndCheck(mip, MipSolver::OPTIMAL, expected_opt);
104
105
106
107}
108
109
110int main()
111{
112
113#ifdef HAVE_GLPK
114  {
115    GlpkMip mip1;
116    aTest(mip1);
117  }
118#endif
119
120#ifdef HAVE_CPLEX
121  try {
122    CplexMip mip2;
123    aTest(mip2);
124  } catch (CplexEnv::LicenseError& error) {
125#ifdef LEMON_FORCE_CPLEX_CHECK
126    check(false, error.what());
127#else
128    std::cerr << error.what() << std::endl;
129    std::cerr << "Cplex license check failed, lp check skipped" << std::endl;
130#endif
131  }
132#endif
133
134  return 0;
135
136}
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