source: lemon-0.x/src/lemon/lp_glpk.cc @ 1312:48f9299b390d

/* -*- C++ -*-
 * src/lemon/lp_glpk.cc - Part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
 * (Egervary Combinatorial Optimization Research Group, EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#ifndef LEMON_LP_GLPK_CC
#define LEMON_LP_GLPK_CC

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

#include <lemon/lp_glpk.h>

namespace lemon {

    /// \e
    int LpGlpk::_addCol() { 
        int i=lpx_add_cols(lp, 1);
        _setColLowerBound(i, -INF);
        _setColUpperBound(i, INF);
        return i;
    }

    /// \e
    int LpGlpk::_addRow() { 
        int i=lpx_add_rows(lp, 1);
        return i;
    }

  
    void LpGlpk::_setRowCoeffs(int i, 
                               int length,
                               const int   * indices, 
                               const Value   * values )
    {
      lpx_set_mat_row(lp, i, length,
                      const_cast<int * >(indices) ,
                      const_cast<Value * >(values));
    }
  
    void LpGlpk::_setColCoeffs(int i, 
                               int length,
                               const int   * indices, 
                               const Value   * values)
    {
      lpx_set_mat_col(lp, i, length,
                      const_cast<int * >(indices),
                      const_cast<Value * >(values));
    }
  
    void LpGlpk::_setColLowerBound(int i, Value lo)
    {
      if (lo==INF) {
        //FIXME error
      }
      int b=lpx_get_col_type(lp, i);
      double up=lpx_get_col_ub(lp, i);  
      if (lo==-INF) {
        switch (b) {
        case LPX_FR:
        case LPX_LO:
          lpx_set_col_bnds(lp, i, LPX_FR, lo, up);
          break;
        case LPX_UP:
          break;
        case LPX_DB:
        case LPX_FX:
          lpx_set_col_bnds(lp, i, LPX_UP, lo, up);
          break;
        default: ;
          //FIXME error
        }
      } else {
        switch (b) {
        case LPX_FR:
        case LPX_LO:
          lpx_set_col_bnds(lp, i, LPX_LO, lo, up);
          break;
        case LPX_UP:      
        case LPX_DB:
        case LPX_FX:
          if (lo==up) 
            lpx_set_col_bnds(lp, i, LPX_FX, lo, up);
          else 
            lpx_set_col_bnds(lp, i, LPX_DB, lo, up);
          break;
        default: ;
          //FIXME error
        }
      }

    }
  
    void LpGlpk::_setColUpperBound(int i, Value up)
    {
      if (up==-INF) {
        //FIXME error
      }
      int b=lpx_get_col_type(lp, i);
      double lo=lpx_get_col_lb(lp, i);
      if (up==INF) {
        switch (b) {
        case LPX_FR:
        case LPX_LO:
          break;
        case LPX_UP:
          lpx_set_col_bnds(lp, i, LPX_FR, lo, up);
          break;
        case LPX_DB:
        case LPX_FX:
          lpx_set_col_bnds(lp, i, LPX_LO, lo, up);
          break;
        default: ;
          //FIXME error
        }
      } else {
        switch (b) {
        case LPX_FR:
          lpx_set_col_bnds(lp, i, LPX_UP, lo, up);
          break;
        case LPX_UP:
          lpx_set_col_bnds(lp, i, LPX_UP, lo, up);
          break;
        case LPX_LO:
        case LPX_DB:
        case LPX_FX:
          if (lo==up) 
            lpx_set_col_bnds(lp, i, LPX_FX, lo, up);
          else 
            lpx_set_col_bnds(lp, i, LPX_DB, lo, up);
          break;
        default: ;
          //FIXME error
        }
      }
    }
  
    void LpGlpk::_setRowLowerBound(int i, Value lo)
    {
      if (lo==INF) {
        //FIXME error
      }
      int b=lpx_get_row_type(lp, i);
      double up=lpx_get_row_ub(lp, i);  
      if (lo==-INF) {
        switch (b) {
        case LPX_FR:
        case LPX_LO:
          lpx_set_row_bnds(lp, i, LPX_FR, lo, up);
          break;
        case LPX_UP:
          break;
        case LPX_DB:
        case LPX_FX:
          lpx_set_row_bnds(lp, i, LPX_UP, lo, up);
          break;
        default: ;
          //FIXME error
        }
      } else {
        switch (b) {
        case LPX_FR:
        case LPX_LO:
          lpx_set_row_bnds(lp, i, LPX_LO, lo, up);
          break;
        case LPX_UP:      
        case LPX_DB:
        case LPX_FX:
          if (lo==up) 
            lpx_set_row_bnds(lp, i, LPX_FX, lo, up);
          else 
            lpx_set_row_bnds(lp, i, LPX_DB, lo, up);
          break;
        default: ;
          //FIXME error
        }
      }
    }
  
  void LpGlpk::_setRowUpperBound(int i, Value up)
  {
    if (up==-INF) {
      //FIXME error
    }
    int b=lpx_get_row_type(lp, i);
    double lo=lpx_get_row_lb(lp, i);
    if (up==INF) {
      switch (b) {
      case LPX_FR:
      case LPX_LO:
        break;
      case LPX_UP:
        lpx_set_row_bnds(lp, i, LPX_FR, lo, up);
        break;
      case LPX_DB:
      case LPX_FX:
        lpx_set_row_bnds(lp, i, LPX_LO, lo, up);
        break;
      default: ;
        //FIXME error
      }
    } else {
      switch (b) {
      case LPX_FR:
        lpx_set_row_bnds(lp, i, LPX_UP, lo, up);
        break;
      case LPX_UP:
        lpx_set_row_bnds(lp, i, LPX_UP, lo, up);
        break;
      case LPX_LO:
      case LPX_DB:
      case LPX_FX:
        if (lo==up) 
          lpx_set_row_bnds(lp, i, LPX_FX, lo, up);
        else 
          lpx_set_row_bnds(lp, i, LPX_DB, lo, up);
        break;
      default: ;
        //FIXME error
      }
    }
  }
  
  void LpGlpk::_setObjCoeff(int i, Value obj_coef)
  {
    lpx_set_obj_coef(lp, i, obj_coef);
  }


  LpGlpk::SolveExitStatus LpGlpk::_solve()
  {
    int i=  lpx_simplex(lp);
    switch (i) {
    case LPX_E_OK: 
      return SOLVED;
      break;
    default:
      return UNSOLVED;
    }
  }

  LpGlpk::Value LpGlpk::_getPrimal(int i)
  {
    return lpx_get_col_prim(lp,i);
  }
  
  LpGlpk::Value LpGlpk::_getPrimalValue()
  {
    return 0;
  }
  
 
  LpGlpk::SolutionStatus LpGlpk::_getPrimalStatus()
  {
    int stat=  lpx_get_status(lp);
    switch (stat) {
    case LPX_UNDEF://Undefined (no solve has been run yet)
      return UNDEFINED;
      break;
    case LPX_NOFEAS://There is no feasible solution (primal, I guess)
    case LPX_INFEAS://Infeasible 
      return INFEASIBLE;
      break;
    case LPX_UNBND://Unbounded
      return INFINITE;
      break;
    case LPX_FEAS://Feasible
      return FEASIBLE;
      break;
    case LPX_OPT://Feasible
      return OPTIMAL;
      break;
    default:
      return UNDEFINED; //to avoid gcc warning
      //FIXME error
    }
  }


  void LpGlpk::_setMax()
  {
  }
  void LpGlpk::_setMin()
  {
  }

 
} //END OF NAMESPACE LEMON

#endif //LEMON_LP_GLPK_CC