/*

 * Reads a polyhedron file on stdin , with rationals and outputs 

 * an approximation in decimal floating point

 * 

 * David Bremner. bremner@cs.mcgill.ca

 *

 */

/*  Hacked by DA, April 20 2006  

 *  

 *  first argument overides stdin

 *  if column 0=0 then first non zero column scaled to +/-1   (otherwise big ugly integers come out)

*/

static char rcsid[]="$Id: rat2float.c,v 1.2 2006/04/04 12:33:38 bremner Exp $";

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <float.h>

FILE *lrs_ifp;                  /* input file pointer       */

#define DOCSTRING "\n\

$Id: rat2float.ds,v 1.3 2006/04/04 12:34:35 bremner Exp $ \n\

\n\

float takes a polytope file with rational or integer coefficents, \n\

and outputs an approximately equivelent one with floating point \n\

coefficents.\n\

\n\

WARNING: Assumes that numerator and denominator will fit  in long integer,\n\

unless compiled with multiprecision support.\n\

\n\

\n\

\n\

"

int usage(){ fprintf(stderr,"\n%s\n",rcsid);fprintf(stderr,DOCSTRING);  exit(1);        }

#define CHECK_HELP   if (argc > 1 && argv[1][0]=='-' && argv[1][1]=='h') usage();

#ifdef LRSMP

#include "lrsmp.h"

#endif

#ifndef LRSMP

typedef  long integer_t;

#define zero(n) (n==0)

#define one(n) (n==1)

#define pmp(s,n) printf("%s %d ",s,n)

#define readrat(n,d) my_readrat(&n,&d);

void my_readrat(long *num_p, long * denom_p) {

  char  buf[BUFSIZ];

  char *p;

  fscanf(lrs_ifp,"%s",buf);

  if (p=index(buf,'/')){

    *p=0;

    *denom_p=atol(&p[1]);

  } else {

    *denom_p=1;

  }

  *num_p=atol(buf);

}

void rattodouble(integer_t num, integer_t denom, double *out_p){

  *out_p=(double)num/(double)denom;

}

#else

typedef  lrs_mp integer_t;

#define MP_DIGITS 1000L

#endif

int main(argc,argv)

     int argc;

     char **argv;

{

  long int  n;

  int j;

  integer_t num,denom,sdenom;

  double out;

  int scale;     /* if column 0 is zero, scale column 1 to 1 */

  char format[BUFSIZ];

  char  buf[BUFSIZ];

  char  inputm[BUFSIZ];

  CHECK_HELP;

  if(argc > 1 )

                       /* command line argument overides stdin   */

    {

      if ((lrs_ifp = fopen (argv[1], "r")) == NULL)

        {

          printf ("\nBad input file name\n");

          return(1);

        }

    }

   else

       lrs_ifp=stdin;

#ifdef LRSMP

  lrs_mp_init (MP_DIGITS,lrs_ifp,stdout);   

#endif

  sprintf(format,"%%.%dlf ",DBL_DIG);

  while ( fgets(buf,BUFSIZ,lrs_ifp) !=NULL )

    {

      fputs(buf,stdout);

      if (strncmp(buf,"begin",5)==0) break;

    }

/* in lrs output m is undefined */

  if (fscanf(lrs_ifp,"%s %ld %s",inputm,&n,buf)==EOF){

    fprintf(stderr,"No begin line");

    exit(1);

  }

  printf("%s %ld real\n",inputm,n);

/*  for (i=0;i<m;i++)    for filtering lrs output we do not know m */

    while (readrat(num,denom)!=999L)

    {

/* If column zero is zero lrs output is integer, so we scale by number in column one */

      if (zero(num))

         scale=TRUE;

      else

         scale=FALSE;

      pmp("",num);

  /* read in numbers */

      for(j=1;j<n;j++)

    {

          readrat(num,denom);

          if((scale==TRUE) && ( j==1) )

             {

               copy(sdenom,num);

               storesign(sdenom,POS);      /* or else inequality is reversed .... */

             }

      if (zero(num)) {

        printf(" 0 ");

      } else {

        if (one(denom)){

              if (scale==TRUE)

                 {

                   rattodouble(num,sdenom,&out);

                   printf(format, out);

                 }

              else

              pmp("",num);

        } else {

          rattodouble(num,denom,&out);

          printf(format, out);

        }

      }

    }

      fputs("\n",stdout);

    }

  fputs("end\n",stdout);

  fgets(buf,BUFSIZ,lrs_ifp);  /* clean off last line */

  while (fgets(buf,BUFSIZ,lrs_ifp) !=NULL )

    {

      fputs(buf,stdout);

    }

return 0;

}