Initial Commit

lib/ldpc/pchk-to-alist.c

@@ -0,0 +1,166 @@
+/* ALIST-TO-PCHK.C - Convert a parity check matrix to alist format. */
+
+/* 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 <string.h>
+#include <math.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 *alist_file, *pchk_file;
+  FILE *af, *pf;
+  int mxrw, mxcw;
+  int *rw, *cw;
+  int i, j, k;
+  mod2entry *e;
+  int trans;
+  int nozeros;
+  int last;
+
+  trans = 0;
+  nozeros = 0;
+
+  for (;;)
+  {
+    if (argc>1 && strcmp(argv[1],"-t")==0)
+    { trans = 1;
+      argc -= 1;
+      argv += 1;
+    }
+    else if (argc>1 && strcmp(argv[1],"-z")==0)
+    { nozeros = 1;
+      argc -= 1;
+      argv += 1;
+    }
+    else
+    { break;
+    }
+  }
+
+  if (argc!=3)
+  { usage();
+  }
+
+  pchk_file = argv[1];
+  alist_file = argv[2];
+
+  read_pchk(pchk_file);
+
+  if (trans)
+  { mod2sparse *HT;
+    HT = H;
+    H = mod2sparse_allocate(N,M);
+    mod2sparse_transpose(HT,H);
+    M = mod2sparse_rows(H);
+    N = mod2sparse_cols(H);
+  }
+
+  af = open_file_std(alist_file,"wb");
+
+  if (af==NULL) 
+  { fprintf(stderr,"Can't create alist file: %s\n",alist_file);
+    exit(1);
+  }
+
+  fprintf(af,"%d %d\n",M,N);
+
+  rw = (int *) chk_alloc (M, sizeof *rw);
+  mxrw = 0;
+
+  for (i = 0; i<M; i++)
+  { rw[i] = mod2sparse_count_row(H,i);
+    if (rw[i]>mxrw)
+    { mxrw = rw[i];
+    }
+  }
+
+  cw = (int *) chk_alloc (N, sizeof *cw);
+  mxcw = 0;
+
+  for (j = 0; j<N; j++)
+  { cw[j] = mod2sparse_count_col(H,j);
+    if (cw[j]>mxcw)
+    { mxcw = cw[j];
+    }
+  }
+
+  fprintf(af,"%d %d\n",mxrw,mxcw);
+
+  for (i = 0; i<M; i++)
+  { fprintf(af,"%d%c",rw[i],i==M-1?'\n':' ');
+  }
+
+  for (j = 0; j<N; j++)
+  { fprintf(af,"%d%c",cw[j],j==N-1?'\n':' ');
+  }
+
+  for (i = 0; i<M; i++)
+  { e = mod2sparse_first_in_row(H,i);
+    last = 0;
+    for (k = 0; !last; k++)
+    { last = nozeros ? k==rw[i]-1 : k==mxrw-1;
+      fprintf (af, "%d%c", mod2sparse_at_end(e)?0:mod2sparse_col(e)+1,
+                           last?'\n':' ');
+      if (!mod2sparse_at_end(e)) 
+      { e = mod2sparse_next_in_row(e);
+      }
+    }
+  }
+
+  for (j = 0; j<N; j++)
+  { e = mod2sparse_first_in_col(H,j);
+    last = 0;
+    for (k = 0; !last; k++)
+    { last = nozeros ? k==cw[j]-1 : k==mxcw-1;
+      fprintf (af, "%d%c", mod2sparse_at_end(e)?0:mod2sparse_row(e)+1,
+                           last?'\n':' ');
+      if (!mod2sparse_at_end(e)) 
+      { e = mod2sparse_next_in_col(e);
+      }
+    }
+  }
+
+  if (ferror(af) || fclose(af)!=0)
+  { fprintf(stderr,"Error writing to alist file %s\n",alist_file);
+    exit(1);
+  }
+
+  return 0;
+}
+
+
+/* PRINT USAGE MESSAGE AND EXIT. */
+
+void usage(void)
+{ fprintf(stderr,"Usage: pchk-to-alist [ -t ] [ -z ] pchk-file alist-file\n");
+  exit(1);
+}