/*# proc: modefilteri - modal filter (frequency-based) for an integer signal# proc:# proc: modesubfilteri - modal filter (frequency-based) for a specified# proc:                  segment of an integer signal*/#include <stdio.h>/***************************************************************************/int *modefilteri(x, n, r)int *x; int n, r;{int *s;int i, h, m;int max_i, max_v, *hist, nbins;int *lptr, *rptr;   if (r % 2 != 1)      fatalerr("modefilteri", "window size", "not odd");   /* size of window should not exceed length of list */   if (r > n){      fprintf(stderr, "Warning: modefilteri\n");      fprintf(stderr, "         specified window exceeds data length,\n");      fprintf(stderr, "         truncating window size from %d to %d,\n", r, n);      fprintf(stderr, "         process proceeding.\n");      r = n;   }   malloc_int(&s, n, "modefilteri : s");   /* initialize histogram in first window */   find_first_max_forward(x, 0, n, &max_i, &max_v);   nbins = max_v + 1;   int_histogram(&hist, nbins, x, r);   find_first_max_forward(hist, 0, nbins, &max_i, &max_v);   /* if length of list equals the size of a single window ... */   if (r == n){      for ( i = 0 ; i < n ; i++ )         s[i] = max_i;      free(hist);      return s;   }   h = (r-1) >> 1;	/* the number of elements either side	*/   for ( i = 0 ; i < h ; i++ )      s[i] = max_i;   lptr = x;   rptr = x+r-1;   for (m = n-h ; i < m ; i++ )   {      (hist[*lptr])--;      (hist[*rptr])++;      if(hist[*rptr] > hist[max_i])         max_i = *rptr;      s[i] = max_i;      lptr++;      rptr++;   }   for (         ; i < n ; i++ )      s[i] = max_i;   free(hist);   return s;}/***************************************************************************/int *modesubfilteri(si, ei, x, n, r)int si, ei;int *x, n, r;{   int in;   int *s;   int i, h, m;   int max_i, max_v, *hist, nbins;   int *lptr, *sptr, *rptr;   in = ei - si + 1;   if(in > n)      fatalerr("modesubfilteri", "sublist exceeds list length", NULL);   if (r % 2 != 1)      fatalerr("modesubfilteri", "window size", "not odd");   /* size of window should not exceed length of list */   if (r > in){      fprintf(stderr, "Warning: modesubfilteri\n");      fprintf(stderr, "         specified window exceeds data length,\n");      fprintf(stderr, "         truncating window size from %d to %d,\n", r, in);      fprintf(stderr, "         process proceeding.\n");      r = in;   }   calloc_int(&s, n, "modesubfilteri: s");   /* initialize histogram in first window */   lptr = x+si;   sptr = s+si;   rptr = x+si+r-1;   find_first_max_forward(lptr, 0, in, &max_i, &max_v);   nbins = max_v + 1;   int_histogram(&hist, nbins, lptr, r);   find_first_max_forward(hist, 0, nbins, &max_i, &max_v);   /* if length of list equals the size of a single window ... */   if (r == in){      for ( i = 0 ; i < in ; i++ ){         (*sptr) = max_i;         sptr++;      }      free(hist);      return s;   }   h = (r-1) >> 1;	/* the number of elements either side	*/   for ( i = 0 ; i < h ; i++ ){      (*sptr) = max_i;      sptr++;   }   for (m = in-h ; i < m ; i++ )   {      (hist[*lptr])--;      (hist[*rptr])++;      if(hist[*rptr] > hist[max_i])         max_i = *rptr;      (*sptr) = max_i;      lptr++;      rptr++;      sptr++;   }   for (         ; i < in ; i++ ){      (*sptr) = max_i;      sptr++;   }   free(hist);   return s;}