[481] | 1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
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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) 2003-2008 |
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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 | extern "C" { |
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| 25 | #include <glpk.h> |
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| 26 | } |
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| 27 | |
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| 28 | #if GLP_MAJOR_VERSION > 4 || (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15) |
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| 29 | #define LEMON_glp(func) (glp_##func) |
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| 30 | #define LEMON_lpx(func) (lpx_##func) |
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| 31 | |
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| 32 | #define LEMON_GLP(def) (GLP_##def) |
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| 33 | #define LEMON_LPX(def) (LPX_##def) |
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| 34 | |
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| 35 | #else |
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| 36 | |
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| 37 | #define LEMON_glp(func) (lpx_##func) |
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| 38 | #define LEMON_lpx(func) (lpx_##func) |
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| 39 | |
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| 40 | #define LEMON_GLP(def) (LPX_##def) |
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| 41 | #define LEMON_LPX(def) (LPX_##def) |
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| 42 | |
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| 43 | #endif |
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| 44 | |
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| 45 | namespace lemon { |
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| 46 | |
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| 47 | MipGlpk::MipGlpk() { |
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| 48 | #if !(GLP_MAJOR_VERSION > 4 || \ |
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| 49 | (GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION > 15)) |
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| 50 | LEMON_lpx(set_class)(lp,LEMON_GLP(MIP)); |
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| 51 | #endif |
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| 52 | } |
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| 53 | |
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| 54 | void MipGlpk::_colType(int i, MipGlpk::ColTypes col_type){ |
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| 55 | switch (col_type){ |
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| 56 | case INT: |
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| 57 | LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(IV)); |
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| 58 | break; |
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| 59 | case REAL: |
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| 60 | LEMON_glp(set_col_kind)(lp,i,LEMON_GLP(CV)); |
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| 61 | break; |
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| 62 | default:; |
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| 63 | //FIXME problem |
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| 64 | } |
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| 65 | } |
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| 66 | |
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| 67 | MipGlpk::ColTypes MipGlpk::_colType(int i) const { |
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| 68 | switch (LEMON_glp(get_col_kind)(lp,i)){ |
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| 69 | case LEMON_GLP(IV): |
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| 70 | return INT;//Or binary |
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| 71 | case LEMON_GLP(CV): |
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| 72 | return REAL; |
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| 73 | default: |
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| 74 | return REAL;//Error! |
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| 75 | } |
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| 76 | |
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| 77 | } |
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| 78 | |
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| 79 | LpGlpk::SolveExitStatus MipGlpk::_solve() { |
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| 80 | int result = LEMON_lpx(simplex)(lp); |
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| 81 | |
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| 82 | // hack: mip does not contain integer variable |
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| 83 | #if GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION == 16 |
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| 84 | int tmp = -1; |
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| 85 | if (LEMON_glp(get_num_int(lp)) == 0) { |
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| 86 | tmp = LEMON_lpx(add_cols)(lp, 1); |
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| 87 | LEMON_glp(set_col_bnds)(lp, tmp, LEMON_GLP(FX), 0.0, 0.0); |
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| 88 | LEMON_glp(set_col_kind)(lp, tmp, LEMON_GLP(IV)); |
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| 89 | } |
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| 90 | #endif |
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| 91 | |
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| 92 | if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)) { |
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| 93 | //Maybe we could try the routine lpx_intopt(lp), a revised |
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| 94 | //version of lpx_integer |
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| 95 | |
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| 96 | result = LEMON_lpx(integer)(lp); |
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| 97 | switch (result){ |
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| 98 | case LEMON_LPX(E_OK): |
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| 99 | solved = true; |
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| 100 | break; |
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| 101 | default: |
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| 102 | solved = false; |
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| 103 | } |
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| 104 | } else { |
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| 105 | solved = false; |
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| 106 | } |
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| 107 | #if GLP_MAJOR_VERSION == 4 && GLP_MINOR_VERSION == 16 |
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| 108 | if (tmp != -1) { |
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| 109 | int tmpa[2]; |
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| 110 | tmpa[1] = tmp; |
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| 111 | LEMON_lpx(del_cols)(lp, 1, tmpa); |
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| 112 | } |
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| 113 | #endif |
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| 114 | return solved ? SOLVED : UNSOLVED; |
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| 115 | } |
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| 116 | |
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| 117 | |
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| 118 | LpGlpk::SolutionStatus MipGlpk::_getMipStatus() const { |
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| 119 | |
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| 120 | if (LEMON_lpx(get_status)(lp)==LEMON_LPX(OPT)){ |
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| 121 | //Meg kell nezni: ha az LP is infinite, akkor ez is, ha az is |
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| 122 | //infeasible, akkor ez is, de ez lehet maskepp is infeasible. |
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| 123 | int stat= LEMON_lpx(mip_status)(lp); |
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| 124 | |
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| 125 | switch (stat) { |
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| 126 | case LEMON_LPX(I_UNDEF)://Undefined (no solve has been run yet) |
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| 127 | return UNDEFINED; |
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| 128 | case LEMON_LPX(I_NOFEAS)://There is no feasible integral solution |
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| 129 | return INFEASIBLE; |
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| 130 | // case LEMON_LPX(UNBND)://Unbounded |
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| 131 | // return INFINITE; |
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| 132 | case LEMON_LPX(I_FEAS)://Feasible |
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| 133 | return FEASIBLE; |
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| 134 | case LEMON_LPX(I_OPT)://Feasible |
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| 135 | return OPTIMAL; |
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| 136 | default: |
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| 137 | return UNDEFINED; //to avoid gcc warning |
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| 138 | //FIXME error |
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| 139 | } |
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| 140 | } |
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| 141 | else |
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| 142 | return UNDEFINED; //Maybe we could refine this: what does the LP |
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| 143 | //relaxation look like |
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| 144 | |
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| 145 | } |
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| 146 | |
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| 147 | MipGlpk::Value MipGlpk::_getPrimal(int i) const { |
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| 148 | return LEMON_glp(mip_col_val)(lp,i); |
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| 149 | } |
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| 150 | |
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| 151 | MipGlpk::Value MipGlpk::_getPrimalValue() const { |
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| 152 | return LEMON_glp(mip_obj_val)(lp); |
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| 153 | } |
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| 154 | } //END OF NAMESPACE LEMON |
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