lemon-0.x: lemon/mip_glpk.cc@4a10a45d55f6

     1 /* -*- C++ -*-

     2  *

     3  * This file is a part of LEMON, a generic C++ optimization library

     4  *

     5  * Copyright (C) 2003-2006

     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  */

    19 #ifndef LEMON_ILP_GLPK_CC

    20 #define LEMON_ILP_GLPK_CC

    22 ///\file

    23 ///\brief Implementation of the LEMON-GLPK lp solver interface.

    25 #include <lemon/mip_glpk.h>

    27 namespace lemon {

    29   MipGlpk::MipGlpk() {

    30     lpx_set_class(lp,LPX_MIP);

    31   }

    33   void MipGlpk::_colType(int i, MipGlpk::ColTypes col_type){

    34     switch (col_type){

    35       case INTEGER:

    36 	lpx_set_col_kind(lp,i,LPX_IV);

    37 	break;

    38       case REAL:

    39 	lpx_set_col_kind(lp,i,LPX_CV);

    40 	break;

    41     default:;

    42         //FIXME problem

    43     }

    44   }

    46   MipGlpk::ColTypes MipGlpk::_colType(int i){

    47     switch (lpx_get_col_kind(lp,i)){

    48     case LPX_IV:

    49       return INTEGER;//Or binary

    50     case LPX_CV:

    51       return REAL;

    52     default:

    53       return REAL;//Error!

    54     }

    56   }

    58   LpGlpk::SolveExitStatus MipGlpk::_solve(){

    59     int result = lpx_simplex(lp);

    60     //

    61     if (lpx_get_status(lp)==LPX_OPT){

    62       //Maybe we could try the routine lpx_intopt(lp), a revised

    63       //version of lpx_integer

    64       result = lpx_integer(lp);

    65       switch (result){

    66       case LPX_E_OK:

    67 	return SOLVED;

    68       default:

    69 	return UNSOLVED;

    70       }

    72     }

    73     return UNSOLVED;

    74   }

    77   LpGlpk::SolutionStatus MipGlpk::_getMipStatus(){

    79     if (lpx_get_status(lp)==LPX_OPT){

    80       //Meg kell nezni: ha az LP is infinite, akkor ez is, ha az is

    81       //infeasible, akkor ez is, de ez lehet maskepp is infeasible.

    82       int stat=  lpx_mip_status(lp);

    84       switch (stat) {

    85       case LPX_I_UNDEF://Undefined (no solve has been run yet)

    86 	return UNDEFINED;

    87       case LPX_I_NOFEAS://There is no feasible integral solution

    88 	return INFEASIBLE;

    89 	//     case LPX_UNBND://Unbounded

    90 	//       return INFINITE;

    91       case LPX_I_FEAS://Feasible

    92 	return FEASIBLE;

    93       case LPX_I_OPT://Feasible

    94 	return OPTIMAL;

    95       default:

    96       return UNDEFINED; //to avoid gcc warning

    97       //FIXME error

    98       }

    99     }

   100     else

   101       return UNDEFINED; //Maybe we could refine this: what does the LP

   102 			//relaxation look like

   104   }

   106   MipGlpk::Value MipGlpk::_getPrimal(int i){

   107     return lpx_mip_col_val(lp,i);

   108   }

   110   MipGlpk::Value MipGlpk::_getPrimalValue(){

   111     return lpx_mip_obj_val(lp);

   112   }

   113 } //END OG NAMESPACE LEMON

   115 #endif

author	deba
	Thu, 14 Sep 2006 19:58:29 +0000
changeset 2217	4a10a45d55f6
parent 2185	e2bf51eab7f7
child 2218	50f1a780a5ff
permissions	-rw-r--r--