Line | |
---|

1 | #include <lemon/lp.h> |
---|

2 | #include "test_tools.h" |
---|

3 | |
---|

4 | using namespace lemon; |
---|

5 | |
---|

6 | void solveAndCheck(Mip& lp, LpSolverBase::SolutionStatus stat, |
---|

7 | double exp_opt) { |
---|

8 | using std::string; |
---|

9 | lp.solve(); |
---|

10 | //int decimal,sign; |
---|

11 | std::ostringstream buf; |
---|

12 | buf << "Primalstatus should be: " << int(stat)<<" and it is "<<int(lp.primalStatus()); |
---|

13 | |
---|

14 | // itoa(stat,buf1, 10); |
---|

15 | check(lp.mipStatus()==stat, buf.str()); |
---|

16 | |
---|

17 | if (stat == LpSolverBase::OPTIMAL) { |
---|

18 | std::ostringstream buf; |
---|

19 | buf << "Wrong optimal value: the right optimum is " << exp_opt; |
---|

20 | check(std::abs(lp.primalValue()-exp_opt) < 1e-3, buf.str()); |
---|

21 | //+ecvt(exp_opt,2) |
---|

22 | } |
---|

23 | } |
---|

24 | |
---|

25 | void aTest(Mip& mip) |
---|

26 | { |
---|

27 | //The following example is very simple |
---|

28 | |
---|

29 | typedef Mip::Row Row; |
---|

30 | typedef Mip::Col Col; |
---|

31 | |
---|

32 | |
---|

33 | Col x1 = mip.addCol(); |
---|

34 | Col x2 = mip.addCol(); |
---|

35 | |
---|

36 | |
---|

37 | |
---|

38 | |
---|

39 | |
---|

40 | |
---|

41 | //Objective function |
---|

42 | mip.setObj(x1); |
---|

43 | |
---|

44 | mip.max(); |
---|

45 | |
---|

46 | |
---|

47 | //Unconstrained optimization |
---|

48 | mip.solve(); |
---|

49 | //Check it out! |
---|

50 | |
---|

51 | //Constraints |
---|

52 | mip.addRow(2*x1+x2 <=2); |
---|

53 | mip.addRow(x1-2*x2 <=0); |
---|

54 | |
---|

55 | //Nonnegativity of the variable x1 |
---|

56 | mip.colLowerBound(x1, 0); |
---|

57 | |
---|

58 | |
---|

59 | |
---|

60 | //Maximization of x1 |
---|

61 | //over the triangle with vertices |
---|

62 | double expected_opt=4.0/5.0; |
---|

63 | solveAndCheck(mip, Mip::OPTIMAL, expected_opt); |
---|

64 | |
---|

65 | //Restrict x2 to integer |
---|

66 | mip.colType(x2,Mip::INTEGER); |
---|

67 | expected_opt=1.0/2.0; |
---|

68 | solveAndCheck(mip, Mip::OPTIMAL, expected_opt); |
---|

69 | |
---|

70 | |
---|

71 | //Restrict both to integer |
---|

72 | mip.colType(x1,Mip::INTEGER); |
---|

73 | expected_opt=0; |
---|

74 | solveAndCheck(mip, Mip::OPTIMAL, expected_opt); |
---|

75 | |
---|

76 | |
---|

77 | |
---|

78 | } |
---|

79 | |
---|

80 | |
---|

81 | int main() |
---|

82 | { |
---|

83 | |
---|

84 | #ifdef HAVE_GLPK |
---|

85 | MipGlpk mip1; |
---|

86 | aTest(mip1); |
---|

87 | #endif |
---|

88 | |
---|

89 | return 0; |
---|

90 | |
---|

91 | } |
---|

**Note:** See

TracBrowser
for help on using the repository browser.