athos@2144: /* -*- C++ -*-
athos@2144:  *
athos@2144:  * This file is a part of LEMON, a generic C++ optimization library
athos@2144:  *
athos@2144:  * Copyright (C) 2003-2006
athos@2144:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
athos@2144:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
athos@2144:  *
athos@2144:  * Permission to use, modify and distribute this software is granted
athos@2144:  * provided that this copyright notice appears in all copies. For
athos@2144:  * precise terms see the accompanying LICENSE file.
athos@2144:  *
athos@2144:  * This software is provided "AS IS" with no warranty of any kind,
athos@2144:  * express or implied, and with no claim as to its suitability for any
athos@2144:  * purpose.
athos@2144:  *
athos@2144:  */
athos@2144: 
athos@2144: ///\file
athos@2218: ///\brief Implementation of the LEMON-GLPK mip solver interface.
athos@2144: 
athos@2144: #include <lemon/mip_glpk.h>
athos@2144: 
athos@2144: namespace lemon {
athos@2144:   
athos@2144:   MipGlpk::MipGlpk() {
athos@2144:     lpx_set_class(lp,LPX_MIP);
athos@2144:   }
athos@2148: 
athos@2149:   void MipGlpk::_colType(int i, MipGlpk::ColTypes col_type){
athos@2148:     switch (col_type){
athos@2267:       case INT:
athos@2148: 	lpx_set_col_kind(lp,i,LPX_IV);
athos@2148: 	break;
athos@2148:       case REAL:
athos@2148: 	lpx_set_col_kind(lp,i,LPX_CV);
athos@2148: 	break;
athos@2149:     default:;
athos@2148:         //FIXME problem
athos@2144:     }
athos@2144:   }
athos@2144:   
deba@2366:   MipGlpk::ColTypes MipGlpk::_colType(int i) const {
athos@2148:     switch (lpx_get_col_kind(lp,i)){
athos@2148:     case LPX_IV:
athos@2267:       return INT;//Or binary
athos@2148:     case LPX_CV:
athos@2148:       return REAL;
athos@2148:     default:
athos@2148:       return REAL;//Error!
athos@2144:     }
athos@2148:     
athos@2144:   }
athos@2144:   
deba@2366:   LpGlpk::SolveExitStatus MipGlpk::_solve() {
athos@2144:     int result = lpx_simplex(lp);
athos@2213:     //
athos@2213:     if (lpx_get_status(lp)==LPX_OPT){
athos@2213:       //Maybe we could try the routine lpx_intopt(lp), a revised
athos@2213:       //version of lpx_integer
athos@2213:       result = lpx_integer(lp);
athos@2213:       switch (result){
athos@2144:       case LPX_E_OK:
athos@2213: 	return SOLVED;
athos@2144:       default:
athos@2213: 	return UNSOLVED;
athos@2213:       }
athos@2213:       
athos@2144:     }
athos@2213:     return UNSOLVED;
athos@2144:   }
athos@2185: 
athos@2185: 
deba@2366:   LpGlpk::SolutionStatus MipGlpk::_getMipStatus() const {
athos@2185: 
athos@2213:     if (lpx_get_status(lp)==LPX_OPT){
athos@2213:       //Meg kell nezni: ha az LP is infinite, akkor ez is, ha az is
athos@2213:       //infeasible, akkor ez is, de ez lehet maskepp is infeasible.
athos@2213:       int stat=  lpx_mip_status(lp);
athos@2213:       
athos@2213:       switch (stat) {
athos@2213:       case LPX_I_UNDEF://Undefined (no solve has been run yet)
athos@2213: 	return UNDEFINED;
athos@2213:       case LPX_I_NOFEAS://There is no feasible integral solution
athos@2213: 	return INFEASIBLE;
athos@2213: 	//     case LPX_UNBND://Unbounded
athos@2213: 	//       return INFINITE;
athos@2213:       case LPX_I_FEAS://Feasible
athos@2213: 	return FEASIBLE;
athos@2213:       case LPX_I_OPT://Feasible
athos@2213: 	return OPTIMAL;
athos@2213:       default:
athos@2185:       return UNDEFINED; //to avoid gcc warning
athos@2185:       //FIXME error
athos@2213:       }
athos@2185:     }
athos@2213:     else 
athos@2213:       return UNDEFINED; //Maybe we could refine this: what does the LP
athos@2213: 			//relaxation look like
athos@2213:       
athos@2185:   }  
athos@2185: 
deba@2366:   MipGlpk::Value MipGlpk::_getPrimal(int i) const {
athos@2144:     return lpx_mip_col_val(lp,i);
athos@2144:   }
athos@2144:   
deba@2366:   MipGlpk::Value MipGlpk::_getPrimalValue() const {
athos@2144:     return lpx_mip_obj_val(lp);
athos@2144:   }
athos@2218: } //END OF NAMESPACE LEMON