COIN-OR::LEMON - Graph Library

source: lemon-0.x/test/mip_test.cc @ 2227:809b18050520

Last change on this file since 2227:809b18050520 was 2227:809b18050520, checked in by Balazs Dezso, 18 years ago

include just the existing solvers

File size: 1.8 KB
Line 
1#include "test_tools.h"
2
3
4#ifdef HAVE_CONFIG_H
5#include <config.h>
6#endif
7
8#ifdef HAVE_CPLEX
9#include <lemon/mip_cplex.h>
10#endif
11
12#ifdef HAVE_GLPK
13#include <lemon/mip_glpk.h>
14#endif
15
16
17using namespace lemon;
18
19void solveAndCheck(MipSolverBase& lp, MipSolverBase::SolutionStatus stat,
20                   double exp_opt) {
21  using std::string;
22
23  lp.solve();
24  //int decimal,sign;
25  std::ostringstream buf;
26  buf << "Primalstatus should be: " << int(stat)<<" and it is "<<int(lp.primalStatus());
27
28
29  //  itoa(stat,buf1, 10);
30  check(lp.mipStatus()==stat, buf.str());
31
32  if (stat ==  MipSolverBase::OPTIMAL) {
33    std::ostringstream buf;
34    buf << "Wrong optimal value: the right optimum is " << exp_opt;
35    check(std::abs(lp.primalValue()-exp_opt) < 1e-3, buf.str());
36    //+ecvt(exp_opt,2)
37  }
38}
39
40void aTest(MipSolverBase& mip)
41{
42 //The following example is very simple
43
44
45  typedef MipSolverBase::Row Row;
46  typedef MipSolverBase::Col Col;
47
48
49
50  Col x1 = mip.addCol();
51  Col x2 = mip.addCol();
52
53
54  //Objective function
55  mip.setObj(x1);
56
57  mip.max();
58
59
60  //Unconstrained optimization
61  mip.solve();
62  //Check it out!
63
64  //Constraints
65  mip.addRow(2*x1+x2 <=2); 
66  mip.addRow(x1-2*x2 <=0); 
67
68  //Nonnegativity of the variable x1
69  mip.colLowerBound(x1, 0);
70
71
72
73  //Maximization of x1
74  //over the triangle with vertices (0,0),(4/5,2/5),(0,2)
75  double expected_opt=4.0/5.0;
76  solveAndCheck(mip, MipSolverBase::OPTIMAL, expected_opt);
77
78  //Restrict x2 to integer
79  mip.colType(x2,MipSolverBase::LEMON_INTEGER); 
80  expected_opt=1.0/2.0;
81  solveAndCheck(mip, MipSolverBase::OPTIMAL, expected_opt);
82
83
84  //Restrict both to integer
85  mip.colType(x1,MipSolverBase::LEMON_INTEGER); 
86  expected_opt=0;
87  solveAndCheck(mip, MipSolverBase::OPTIMAL, expected_opt);
88
89 
90
91}
92
93
94int main()
95{
96
97#ifdef HAVE_GLPK
98  MipGlpk mip1;
99  aTest(mip1);
100#endif
101
102#ifdef HAVE_CPLEX
103  MipCplex mip2;
104  aTest(mip2);
105#endif
106
107  return 0;
108
109}
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