bci.c

数据挖掘中的bayes算法,很好的代码

    printf("tabfile  table file to read "
                    "(field names in first record)\n");
    printf("bcfile   file to write Bayes classifier to\n");
    return 0;                   /* print a usage message */
  }                             /* and abort the program */

  /* --- evaluate arguments --- */
  for (i = 1; i < argc; i++) {  /* traverse arguments */
    s = argv[i];                /* get option argument */
    if (optarg) { *optarg = s; optarg = NULL; continue; }
    if ((*s == '-') && *++s) {  /* -- if argument is an option */
      while (1) {               /* traverse characters */
        switch (*s++) {         /* evaluate option */
          case 'F': full    = 1;                     break;
          case 'c': optarg  = &clsname;              break;
          case 'w': balance = (*s) ? *s++ : 0;       break;
          case 's': simp    = (*s) ? *s++ : 0;       break;
          case 'L': lcorr   =      strtod(s, &s);    break;
          case 't': setup  |= NBC_DWNULL;            break;
          case 'm': setup  |= NBC_MAXLLH;            break;
          case 'p': desc   |= NBC_REL;               break;
          case 'l': maxlen  = (int)strtol(s, &s, 0); break;
          case 'b': optarg  = &blanks;               break;
          case 'f': optarg  = &fldseps;              break;
          case 'r': optarg  = &recseps;              break;
          case 'u': optarg  = &nullchs;              break;
          case 'C': optarg  = &comment;              break;
          case 'n': flags  |= AS_WEIGHT;             break;
          case 'd': flags  |= AS_DFLT;               break;
          case 'h': optarg  = &fn_hdr;               break;
          default : error(E_OPTION, *--s);           break;
        }                       /* set option variables */
        if (!*s) break;         /* if at end of string, abort loop */
        if (optarg) { *optarg = s; optarg = NULL; break; }
      } }                       /* get option argument */
    else {                      /* -- if argument is no option */
      switch (k++) {            /* evaluate non-option */
        case  0: fn_dom = s;      break;
        case  1: fn_tab = s;      break;
        case  2: fn_bc  = s;      break;
        default: error(E_ARGCNT); break;
      }                         /* note filenames */
    }
  }
  if (optarg) error(E_OPTARG);  /* check the option argument */
  if (k != 3) error(E_ARGCNT);  /* and the number of arguments */
  if (fn_hdr && (strcmp(fn_hdr, "-") == 0))
    fn_hdr = "";                /* convert "-" to "" */
  i = (!fn_dom || !*fn_dom) ? 1 : 0;
  if  (!fn_tab || !*fn_tab) i++;
  if  ( fn_hdr && !*fn_hdr) i++;/* check assignments of stdin: */
  if (i > 1) error(E_STDIN);    /* stdin must not be used twice */
  if      (simp == 'a') setup |= NBC_ADD;
  else if (simp == 'r') setup |= NBC_REMOVE;
  else if (simp !=  0 )         /* check simplification mode */
    error(E_SIMP, simp);        /* (must be 'add' or 'remove') */
  if ((balance !=  0)  && (balance != 'l')
  &&  (balance != 'b') && (balance != 's'))
    error(E_BALANCE, balance);  /* check balancing mode */
  if (fn_hdr)                   /* set the header file flag */
    flags = AS_ATT | (flags & ~AS_DFLT);

  /* --- read attribute set --- */
  t    = clock();               /* start the timer */
  scan = sc_create(fn_dom);     /* create a scanner */
  if (!scan) error((!fn_dom || !*fn_dom) ? E_NOMEM : E_FOPEN, fn_dom);
  attset = as_create("domains", att_delete);
  if (!attset) error(E_NOMEM);  /* create an attribute set */
  fprintf(stderr, "\nreading %s ... ", sc_fname(scan));
  if ((sc_nexter(scan)   <  0)  /* start scanning (get first token) */
  ||  (as_parse(attset, scan, AT_ALL) != 0)
  ||  (as_attcnt(attset) <= 0)  /* parse attribute set and */
  ||  !sc_eof(scan))            /* check for end of file */
    error(E_PARSE, sc_fname(scan));
  attcnt = as_attcnt(attset);   /* print a success message */
  fprintf(stderr, "[%d attribute(s)] done ", attcnt);
  fprintf(stderr, "[%.2fs].", SEC_SINCE(t));

  /* --- filter attributes --- */
  for (i = attcnt; --i >= 0; ) {
    att = as_att(attset, i);    /* traverse the attributes */
    k   = att_getdir(att);      /* and get their directions */
    att_setmark(att, ((k == DIR_IN) || (k == DIR_OUT)) ? -1 : +1);
  }                             /* mark input and output attributes */
  as_attcut(NULL, attset, AS_MARKED);
  attcnt = as_attcnt(attset);   /* cut all other attributes and */
  for (i = attcnt; --i >= 0; )  /* clear all attribute markers */
    att_setmark(as_att(attset, i), 0);

  /* --- determine id of class column --- */
  if (clsname) {                /* if a class att. name is given */
    for (i = attcnt; --i >= 0;) /* remove all attribute directions */
      att_setdir(as_att(attset, i), DIR_IN);
    clsid = as_attid(attset, clsname);
    if (clsid < 0) error(E_CLASS, clsname, sc_fname(scan)); }
  else {                        /* if no target att. name is given */
    for (clsid = -1, i = attcnt; --i >= 0; ) {
      if (att_getdir(as_att(attset, i)) != DIR_OUT) continue;
      if (clsid < 0) clsid = i; else error(E_MULTCLS);
    }                           /* find a (unique) output attribute */
    if (clsid < 0) clsid = attcnt -1;
  }                             /* by default use the last attribute */
  att = as_att(attset, clsid);  /* get the class attribute and */
  att_setdir(att, DIR_OUT);     /* set the class attribute direction */
  if (att_type(att) != AT_NOM)  /* check the type of the class */
    error(E_CTYPE, att_name(att));        /* (must be nominal) */
  sc_delete(scan); scan = NULL; /* delete the scanner */
  fprintf(stderr, "\n");        /* terminate the startup message */

  /* --- read table header --- */
  as_chars(attset, recseps, fldseps, blanks, nullchs, comment);
  in = io_hdr(attset, fn_hdr, fn_tab, flags, 1);
  if (!in) error(1);            /* read the table header */

  /* --- build naive Bayes classifier --- */
  if (!full                     /* if to induce a naive Bayes class. */
  &&  (balance                  /* and to balance class frequencies */
  ||   simp)) {                 /* or to simplify the classifier */
    table = io_bodyin(attset, in, fn_tab, flags, "table", 2);
    if (!table) error(1);       /* read the table body */
    t = clock();                /* start the timer */
    fprintf(stderr, "reducing%s table ... ",
                    (balance) ? " and balancing" : "");
    tab_reduce(table);          /* reduce table for speed up */
    if (balance) {              /* if the balance flag is set */
      tab_balance(table, clsid, (balance == 'l') ? -2.0F
                              : (balance == 'b') ? -1.0F : 0.0F, NULL);
    }                           /* balance the class frequencies */
    tplwgt = tab_getwgt(table, 0, INT_MAX);
    fprintf(stderr, "[%d/%g tuple(s)] ", tab_tplcnt(table), tplwgt);
    fprintf(stderr, "done [%.2fs].\n", SEC_SINCE(t));
    t = clock();                /* start the timer */
    fprintf(stderr, "building classifier ... ");
    nbc = nbc_induce(table, clsid, setup, lcorr);
    if (!nbc) error(E_NOMEM);   /* induce a classifier and */
    attcnt = nbc_mark(nbc);     /* mark the selected attributes */
    fprintf(stderr, "done [%.2fs].\n", SEC_SINCE(t)); }
  else {                        /* if to build a normal classifier */
    if (full) fbc = fbc_create(attset, clsid);
    else      nbc = nbc_create(attset, clsid);
    if (!fbc && !nbc)           /* create either a full or */
      error(E_NOMEM);           /* a naive Bayes classifier */
    t = clock();                /* start the timer */
    k = AS_INST | (flags & ~(AS_ATT|AS_DFLT));
    i = ((flags & AS_DFLT) && !(flags & AS_ATT))
      ? 0 : as_read(attset, in, k);
    while (i == 0) {            /* record read loop */
      if (((fbc) ? fbc_add(fbc, NULL) : nbc_add(nbc, NULL)) != 0)
        error(E_NOMEM);         /* process tuple and count it */
      tplcnt++; tplwgt += as_getwgt(attset);
      i = as_read(attset, in, k);
    }                           /* try to read the next record */
    if (i < 0) {                /* if an error occurred, */
      err = as_err(attset);     /* get the error information */
      tplcnt += (flags & (AS_ATT|AS_DFLT)) ? 1 : 2;
      io_error(i, fn_tab, tplcnt, err->s, err->fld, err->exp);
      error(1);                 /* print an error message */
    }                           /* and abort the program */
    if (in != stdin) fclose(in);/* close the input file */
    in = NULL;                  /* and set up the classifier */
    if (fbc) { fbc_setup(fbc, setup, lcorr); attcnt = fbc_mark(fbc); }
    else     { nbc_setup(nbc, setup|NBC_ALL, lcorr); }
    fprintf(stderr, "[%d/%g tuple(s)] ", tplcnt, tplwgt);
    fprintf(stderr, "done [%.2fs].\n", SEC_SINCE(t));
  }                             /* print a success message */

  /* --- describe created classifier --- */
  t = clock();                  /* start the timer */
  if (fn_bc && *fn_bc)          /* if an output file name is given, */
    out = fopen(fn_bc, "w");    /* open output file for writing */
  else {                        /* if no output file name is given, */
    out = stdout; fn_bc = "<stdout>"; }     /* write to std. output */
  fprintf(stderr, "writing %s ... ", fn_bc);
  if (!out) error(E_FOPEN, fn_bc);
  k = (full || simp)            /* print only the class and */
    ? AS_MARKED : 0;            /* the marked attributes */
  if (as_desc(attset, out, k|AS_TITLE|AS_IVALS, maxlen) != 0)
    error(E_FWRITE, fn_bc);     /* describe attribute domains */
  fputc('\n', out);             /* leave one line empty */
  k = (simp) ? NBC_MARKED : 0;  /* print only marked attributes */
  if (((fbc) ? fbc_desc(fbc,  out, desc  |FBC_TITLE, maxlen)
  :            nbc_desc(nbc,  out, desc|k|NBC_TITLE, maxlen)) != 0)
    error(E_FWRITE, fn_bc);     /* describe Bayes classifier */
  if (maxlen <= 0) maxlen = 72; /* determine maximal line length */
  fputs("\n/*", out);           /* append additional information */
  for (k = maxlen -2; --k >= 0; ) fputc('-', out);
  fprintf(out, "\n  number of attributes: %d",   attcnt);
  fprintf(out, "\n  number of tuples    : %g\n", tplwgt);
  for (k = maxlen -2; --k >= 0; ) fputc('-', out);
  fputs("*/\n", out);           /* terminate additional information */
  if (out != stdout) {          /* if not written to stdout, */
    k = fclose(out); out = NULL;/* close the output file */
    if (k) error(E_FWRITE, fn_bc);
  }                             /* print a success message */
  fprintf(stderr, "[%d+1 attribute(s)] ", attcnt-1);
  fprintf(stderr, "done [%.2fs].\n", SEC_SINCE(t));

  /* --- clean up --- */
  #ifndef NDEBUG
  if (table) tab_delete(table, 0);  /* delete table, */
  if (nbc)   nbc_delete(nbc, 1);    /* naive Bayes classifier, */
  if (fbc)   fbc_delete(fbc, 1);    /* full Bayes classifier, */
  #endif                            /* and underlying attribute set */
  #ifdef STORAGE
  showmem("at end of program"); /* check memory usage */
  #endif
  return 0;                     /* return 'ok' */
}  /* main() */