1 | /* -*- C++ -*- |
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2 | * |
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3 | * This file is a part of LEMON, a generic C++ optimization library |
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4 | * |
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5 | * Copyright (C) 2003-2007 |
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6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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8 | * |
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9 | * Permission to use, modify and distribute this software is granted |
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10 | * provided that this copyright notice appears in all copies. For |
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11 | * precise terms see the accompanying LICENSE file. |
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12 | * |
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13 | * This software is provided "AS IS" with no warranty of any kind, |
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14 | * express or implied, and with no claim as to its suitability for any |
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15 | * purpose. |
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16 | * |
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17 | */ |
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18 | |
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19 | ///\file |
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20 | ///\brief Implementation of the LEMON-GLPK mip solver interface. |
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21 | |
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22 | #include <lemon/mip_glpk.h> |
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23 | |
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24 | #if GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15) |
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25 | #define LEMON_glp(func) (glp_##func) |
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26 | #define LEMON_lpx(func) (lpx_##func) |
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27 | |
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28 | #define LEMON_GLP(def) (GLP_##def) |
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29 | #define LEMON_LPX(def) (LPX_##def) |
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30 | |
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31 | #else |
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32 | |
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33 | #define LEMON_glp(func) (lpx_##func) |
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34 | #define LEMON_lpx(func) (lpx_##func) |
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35 | |
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36 | #define LEMON_GLP(def) (LPX_##def) |
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37 | #define LEMON_LPX(def) (LPX_##def) |
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38 | |
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39 | #endif |
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40 | |
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41 | namespace lemon { |
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42 | |
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43 | MipGlpk::MipGlpk() { |
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44 | #if !(GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15)) |
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45 | LEMON_lpx(set_class)(lp,LEMON_GLP(MIP)); |
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46 | #endif |
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47 | } |
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48 | |
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49 | void MipGlpk::_colType(int i, MipGlpk::ColTypes col_type){ |
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50 | switch (col_type){ |
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51 | case INT: |
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52 | LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(IV)); |
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53 | break; |
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54 | case REAL: |
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55 | LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(CV)); |
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56 | break; |
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57 | default:; |
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58 | //FIXME problem |
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59 | } |
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60 | } |
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61 | |
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62 | MipGlpk::ColTypes MipGlpk::_colType(int i) const { |
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63 | switch (LEMON_glp(get_col_kind)(lp,i)){ |
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64 | case LEMON_GLP(IV): |
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65 | return INT;//Or binary |
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66 | case LEMON_GLP(CV): |
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67 | return REAL; |
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68 | default: |
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69 | return REAL;//Error! |
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70 | } |
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71 | |
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72 | } |
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73 | |
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74 | LpGlpk::SolveExitStatus MipGlpk::_solve() { |
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75 | int result = LEMON_lpx(simplex)(lp); |
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76 | |
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77 | // hack: mip does not contain integer variable |
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78 | #if GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15) |
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79 | int tmp = -1; |
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80 | if (LEMON_glp(get_num_int(lp)) == 0) { |
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81 | tmp = LEMON_lpx(add_cols)(lp, 1); |
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82 | LEMON_glp(set_col_bnds)(lp, tmp, LEMON_GLP(FX), 0.0, 0.0); |
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83 | LEMON_glp(set_col_kind)(lp, tmp, LEMON_GLP(IV)); |
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84 | } |
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85 | #endif |
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86 | |
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87 | if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)) { |
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88 | //Maybe we could try the routine lpx_intopt(lp), a revised |
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89 | //version of lpx_integer |
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90 | |
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91 | result = LEMON_lpx(integer)(lp); |
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92 | switch (result){ |
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93 | case LEMON_LPX(E_OK): |
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94 | solved = true; |
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95 | break; |
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96 | default: |
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97 | solved = false; |
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98 | } |
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99 | } else { |
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100 | solved = false; |
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101 | } |
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102 | #if GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15) |
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103 | if (tmp != -1) { |
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104 | int tmpa[2]; |
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105 | tmpa[1] = tmp; |
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106 | LEMON_lpx(del_cols)(lp, 1, tmpa); |
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107 | } |
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108 | #endif |
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109 | return solved ? SOLVED : UNSOLVED; |
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110 | } |
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111 | |
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112 | |
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113 | LpGlpk::SolutionStatus MipGlpk::_getMipStatus() const { |
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114 | |
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115 | if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)){ |
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116 | //Meg kell nezni: ha az LP is infinite, akkor ez is, ha az is |
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117 | //infeasible, akkor ez is, de ez lehet maskepp is infeasible. |
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118 | int stat= LEMON_lpx(mip_status)(lp); |
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119 | |
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120 | switch (stat) { |
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121 | case LEMON_LPX(I_UNDEF)://Undefined (no solve has been run yet) |
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122 | return UNDEFINED; |
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123 | case LEMON_LPX(I_NOFEAS)://There is no feasible integral solution |
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124 | return INFEASIBLE; |
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125 | // case LEMON_LPX(UNBND)://Unbounded |
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126 | // return INFINITE; |
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127 | case LEMON_LPX(I_FEAS)://Feasible |
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128 | return FEASIBLE; |
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129 | case LEMON_LPX(I_OPT)://Feasible |
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130 | return OPTIMAL; |
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131 | default: |
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132 | return UNDEFINED; //to avoid gcc warning |
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133 | //FIXME error |
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134 | } |
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135 | } |
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136 | else |
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137 | return UNDEFINED; //Maybe we could refine this: what does the LP |
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138 | //relaxation look like |
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139 | |
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140 | } |
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141 | |
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142 | MipGlpk::Value MipGlpk::_getPrimal(int i) const { |
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143 | return LEMON_glp(mip_col_val)(lp,i); |
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144 | } |
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145 | |
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146 | MipGlpk::Value MipGlpk::_getPrimalValue() const { |
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147 | return LEMON_glp(mip_obj_val)(lp); |
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148 | } |
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149 | } //END OF NAMESPACE LEMON |
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