mt_test.ex.c

Go to the documentation of this file.

/* MTgomory "multi tableau gomory cut" provides an implementation for gomory
 * cuts derived from multiple tableau rows in the spirit of the work of
 * Andersen et al (IPCO 2007), Cornuejols (es presented in George Nemhauser
 * Birthday Conference in Atlanta 2007) and Gomory (presented in the same
 * conference).
 *
 * Copyright (C) 2007 Daniel Espinoza.
 * 
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA 
 * */
/* ========================================================================= */
#include <getopt.h>
#include <math.h>
#include "eg_mem.h"
#include "eg_macros.h"
#include "mt_gomory.h"
#include "mt_tableau.h"
#include "eg_io.h"
/** @file 
 * @ingroup MTgomory */
/** @addtogroup MTgomory */
/** @{ */
/* ========================================================================= */
/** @brief global option variables */
static int mt_mode=0;
static char tb_file[1024]="tableau.txt";
/* ========================================================================= */
/** @brief basic usage function */
int static usage(char*prog)
{
  fprintf(stderr,"Usage:\n%s [options]",prog);
  fprintf(stderr,"Options:\n");
  fprintf(stderr,"  -m n  Mode of testing: 0 for tableau reading testing,\n");
  fprintf(stderr,"        Default: %d\n",mt_mode);
  fprintf(stderr,"  -t f  File containing a tableau row, Default %s\n",tb_file);
  return 0;
}
/* ========================================================================= */
/** @brief parsing code */
int static parse_args(int argc,char**argv)
{
  int c;
  while((c=getopt(argc,argv,"f:m:"))!=EOF)
  {
    switch(c)
    {
      case 'f':
        snprintf(tb_file,1023,"%s",optarg);
        break;
      case 'm':
        mt_mode = atoi(optarg);
        break;
      default:
        usage(argv[0]);
        exit(1);
    }
  }
  /* test consistency if arguments */
  if(mt_mode != 0)
  {
    usage(argv[0]);
    exit(1);
  }
  return 0;
}
/* ========================================================================= */
/** @brief test #MTgomory_cut function, by reading from a file a tableau, and
 * giving it to the function, print the resulting cut, and return */
int static test_MTgomory_cut(void)
{
  int rval = 0;
  register int i;
  int*rowbeg = 0, *rowind = 0, nrows = 0, ncols = 0;
  double* rowval = 0, *f=0, *cutval=0, *work=0, *base = 0;
  FILE*input = EGsfopen(tb_file,"r");
  /* now read the file */
  rval = MTreadRTableau( input, &nrows, &ncols, &rowval, &rowind, 
                         &rowbeg, &f);
  CHECKRVALG(rval,CLEANUP);
  /* now do the cutting */
  cutval = EGsMalloc(double,ncols);
  work = EGsMalloc(double,ncols+1);
  base = EGsMalloc(double,nrows);
  for( i = nrows ; i-- ; ) base[i] = 1.0;
  rval = MTgomoryCut( nrows, ncols, rowval, rowind, rowbeg, f, base,
                      cutval, work);
  CHECKRVALG(rval,CLEANUP);
  /* now we display the cut */
  fprintf(stdout, "The cut is:\n");
  for( i = 0 ; i < ncols ; i++ )
    fprintf(stdout,"%s %.5lf x_%d ", (cutval[i]>=0) ? "+":"-", 
            fabs(cutval[i]), i);
  fprintf(stdout," >= 1\n");
  CLEANUP:
  EGfree(rowbeg);
  EGfree(rowind);
  EGfree(rowval);
  EGfree(f);
  EGfree(cutval);
  EGfree(work);
  EGfree(base);
  fclose(input);
  return rval;
}
/* ========================================================================= */
/** @brief a simple example on its usage */
int main(int argc,char**argv)
{
  int rval = 0;
  parse_args(argc,argv);
  switch(mt_mode)
  {
    case 0:
      rval = test_MTgomory_cut();
      CHECKRVALG(rval,CLEANUP);
      break;
  }
  CLEANUP:
  return rval;
}

/* ========================================================================= */
/** @} */
/* end of mt_test.ex.c */

---