print-gen.c

剑桥大学David J.C. MacKay 个人网站公布的2006年的代码

/* PRINT-CODE.C - Print a Low Density Parity Check code's matrices. */

/* Copyright (c) 2000, 2001 by Radford M. Neal 
 *
 * Permission is granted for anyone to copy, use, modify, or distribute this
 * program and accompanying programs and documents for any purpose, provided 
 * this copyright notice is retained and prominently displayed, along with
 * a note saying that the original programs are available from Radford Neal's
 * web page, and note is made of any changes made to the programs.  The
 * programs and documents are distributed without any warranty, express or
 * implied.  As the programs were written for research purposes only, they have
 * not been tested to the degree that would be advisable in any important
 * application.  All use of these programs is entirely at the user's own risk.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "rand.h"
#include "alloc.h"
#include "open.h"
#include "mod2sparse.h"
#include "mod2dense.h"
#include "mod2convert.h"
#include "rcode.h"

void usage(void);


/* MAIN PROGRAM. */

int main
( int argc,
  char **argv
)
{
  char *gen_file;
  int dprint;
  int i, j;

  dprint = 0;
  if (argc>1 && strcmp(argv[1],"-d")==0)
  { dprint = 1;
    argc -= 1;
    argv += 1;
  }

  if (!(gen_file = argv[1]) || argv[2])
  { usage();
  }

  read_gen(gen_file,0,1);

  switch (type)
  {
    case 's': 
    { 
      printf("\nGenerator matrix in %s (sparse representation):\n\n",gen_file);

      printf("Column order (message bits at end):\n");
      for (j = 0; j<N; j++) 
      { if (j%20==0) printf("\n");
        printf(" %3d",cols[j]);
      }
      printf("\n\n");

      printf("Row order:\n");
      for (i = 0; i<M; i++) 
      { if (i%20==0) printf("\n");
        printf(" %3d",rows[i]); 
      }
      printf("\n\n");

      if (dprint)
      { mod2dense *Ld, *Ud;
        Ld = mod2dense_allocate(M,M);
        Ud = mod2dense_allocate(M,N);
        mod2sparse_to_dense(L,Ld);
        mod2sparse_to_dense(U,Ud);
        printf("L:\n\n");
        mod2dense_print(stdout,Ld);
        printf("\n");
        printf("U:\n\n");
        mod2dense_print(stdout,Ud);
        printf("\n");
      }
      else
      { printf("L:\n\n");
        mod2sparse_print(stdout,L);
        printf("\n");
        printf("U:\n\n");
        mod2sparse_print(stdout,U);
        printf("\n");
      }
     
      break;
    }

    case 'd': case 'm':
    {
      if (type=='d')
      { printf("\nGenerator matrix in %s (dense representation):\n\n",gen_file);
      }
      if (type=='m')
      { printf("\nGenerator matrix in %s (mixed representation):\n\n",gen_file);
      }

      printf("Column order (message bits at end):\n");
      for (j = 0; j<N; j++) 
      { if (j%20==0) printf("\n");
        printf(" %3d",cols[j]);
      }
      printf("\n\n");

      printf (type=='d' ? "Inv(A) X B:\n\n" : "Inv(A):\n\n");
      mod2dense_print(stdout,G);
      printf("\n");

      break;
    }

    default: 
    { fprintf(stderr,"Unknown type of generator matrix file\n");
      exit(1);
    }
  }

  return 0;
}


/* PRINT USAGE MESSAGE AND EXIT. */

void usage(void)
{ fprintf(stderr,"Usage: print-gen [ -d ] gen-file\n");
  exit(1);
}