Initial Commit

lib/ldpc/rand-src.c

@@ -0,0 +1,86 @@
+/* RAND-SRC.C - Generate random message bits. */
+
+/* Copyright (c) 1995-2012 by Radford M. Neal.
+ *
+ * Permission is granted for anyone to copy, use, modify, and distribute
+ * these programs and accompanying documents for any purpose, provided
+ * this copyright notice is retained and prominently displayed, and note
+ * is made of any changes made to these programs.  These 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 <math.h>
+
+#include "open.h"
+#include "rand.h"
+
+void usage(void);
+
+
+/* MAIN PROGRAM. */
+
+int main
+( int argc,
+  char **argv
+)
+{
+  int seed, bs, nb;
+  char *file, *n_bits;
+  char junk;
+  int i, j;
+  FILE *f;
+
+  if (!(file = argv[1])
+   || !argv[2] || sscanf(argv[2],"%d%c",&seed,&junk)!=1
+   || !(n_bits = argv[3])
+   || argv[4])
+  { usage();
+  }
+
+  if (sscanf(n_bits,"%d%c",&nb,&junk)==1)
+  { if (nb<=0) usage();
+    bs = 1;
+  }
+  else if (sscanf(n_bits,"%dx%d%c",&bs,&nb,&junk)==2)
+  { if (nb<=0 || bs<=0) usage();
+  }
+  else
+  { usage();
+  }
+
+  f = open_file_std(file,"w");
+  if (f==NULL)
+  { fprintf(stderr,"Can't create source file: %s\n",file);
+    exit(1);
+  }
+
+  rand_seed(10*seed+2);
+
+  for (i = 0; i<nb; i++)
+  { for (j = 0; j<bs; j++)
+    { fprintf(f,"%d",rand_int(2));
+    }
+    fprintf(f,"\n");
+  }
+
+  if (ferror(f) || fclose(f)!=0) 
+  { fprintf(stderr,"Error writing random source blocks to %s\n",file);
+    exit(1);
+  }
+
+  return 0;
+}
+
+
+/* PRINT USAGE MESSAGE AND EXIT. */
+
+void usage(void)
+{ fprintf(stderr,"Usage: rand-src source-file seed n-bits\n");
+  exit(1);
+}