fpgrowth.c

此为FP-tree增长算法

/*----------------------------------------------------------------------
  File    : fpgrowth.c
  Contents: fpgrowth algorithm for finding frequent item sets
  Author  : Christian Borgelt
  History : 21.11.2004 file created from eclat.c
            22.11.2004 pruning of tree projection to bonsai added
            23.11.2004 absolute/relative support output changed
            09.12.2004 filter added (binary logarithm of supp. quotient)
            20.06.2005 use of flag for "no item sorting" corrected
----------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <float.h>
#include <math.h>
#include <time.h>
#include <assert.h>
#include "scan.h"
#include "fptree.h"
#ifdef STORAGE
#include "storage.h"
#endif

/*----------------------------------------------------------------------
  Preprocessor Definitions
----------------------------------------------------------------------*/
#define PRGNAME     "fpgrowth"
#define DESCRIPTION "find frequent item sets " \
                    "with the fpgrowth algorithm"
#define VERSION     "version 1.8 (2005.12.06)         " \
                    "(c) 2004-2005   Christian Borgelt"

/* --- output flags --- */
#define OF_REL      0x01        /* print relative support */
#define OF_ABS      0x02        /* print absolute support */
#define OF_DEV      0x04        /* print deviation from indep. occ. */
#define OF_SCANF    0x08        /* convert names to scanable form */

/* --- error codes --- */
#define E_OPTION    (-5)        /* unknown option */
#define E_OPTARG    (-6)        /* missing option argument */
#define E_ARGCNT    (-7)        /* too few/many arguments */
#define E_STDIN     (-8)        /* double assignment of stdin */
#define E_SUPP      (-9)        /* invalid item set support */
#define E_ITEMCNT  (-10)        /* invalid number of items */
#define E_NOTAS    (-11)        /* no items or transactions */
#define E_UNKNOWN  (-18)        /* unknown error */

#ifndef QUIET                   /* if not quiet version */
#define MSG(x)        x         /* print messages */
#else                           /* if quiet version */
#define MSG(x)                  /* suppress messages */
#endif

#define SEC_SINCE(t)  ((clock()-(t)) /(double)CLOCKS_PER_SEC)
#define RECCNT(s)     (tfs_reccnt(is_tfscan(s)) \
                      + ((tfs_delim(is_tfscan(s)) == TFS_REC) ? 0 : 1))
#define BUFFER(s)     tfs_buf(is_tfscan(s))

/*----------------------------------------------------------------------
  Constants
----------------------------------------------------------------------*/
#define LN_2       0.69314718055994530942   /* ln(2) */

#ifndef QUIET                   /* if not quiet version */
/* --- error messages --- */
static const char *errmsgs[] = {
  /* E_NONE      0 */  "no error\n",
  /* E_NOMEM    -1 */  "not enough memory\n",
  /* E_FOPEN    -2 */  "cannot open file %s\n",
  /* E_FREAD    -3 */  "read error on file %s\n",
  /* E_FWRITE   -4 */  "write error on file %s\n",
  /* E_OPTION   -5 */  "unknown option -%c\n",
  /* E_OPTARG   -6 */  "missing option argument\n",
  /* E_ARGCNT   -7 */  "wrong number of arguments\n",
  /* E_STDIN    -8 */  "double assignment of standard input\n",
  /* E_SUPP     -9 */  "invalid minimal support %g%%\n",
  /* E_ITEMCNT -10 */  "invalid number of items %d\n",
  /* E_NOTAS   -11 */  "no items or transactions to work on\n",
  /*    -12 to -15 */  NULL, NULL, NULL, NULL,
  /* E_ITEMEXP -16 */  "file %s, record %d: item expected\n",
  /* E_DUPITEM -17 */  "file %s, record %d: duplicate item %s\n",
  /* E_UNKNOWN -18 */  "unknown error\n"
};
#endif

/*----------------------------------------------------------------------
  Global Variables
----------------------------------------------------------------------*/
#ifndef QUIET
static char    *prgname;        /* program name for error messages */
#endif
static ITEMSET *itemset = NULL; /* item set */
static TASET   *taset   = NULL; /* transaction set */
static FPTREE  *fptree  = NULL; /* frequent pattern tree */
static FILE    *in      = NULL; /* input  file */
static FILE    *out     = NULL; /* output file */
static int     tacnt    = 0;    /* number of transactions */
static double  mindev   = -DBL_MAX; /* minimal value of deviation */
static double  *logfs   = NULL;     /* logarithms of item frequencies */
static int     flags    = OF_REL;   /* output flags */
static char    *fmt     = "%.1f";   /* output format for support */
static char    buf[4*TFS_SIZE+4];   /* buffer for formatting */

/*----------------------------------------------------------------------
  Item Set Report Function
----------------------------------------------------------------------*/

static int _report (int *ids, int cnt, int supp, void *data)
{                               /* --- report a frequent item set */
  int        i;                 /* loop variable */
  const char *name;             /* buffer for item name */
  double     dev = 0;           /* deviation from indep. occurrence */

  assert(ids);                  /* check the function arguments */
  if (flags & OF_DEV) {         /* if to filter w.r.t. deviation */
    for (i = cnt; --i >= 0; )   /* traverse the items and */
      dev += logfs[ids[i]];     /* sum the logs of the item freqs. */
    dev = (log(supp/(double)tacnt) -dev) /LN_2;
    if (dev < mindev) return 0; /* compute and check the deviation */
  }                             /* from an independent occurrence */
  for (i = 0; i < cnt; i++) {   /* traverse the item set */
    name = is_name(itemset, ids[i]);
    if (flags & OF_SCANF) {     /* convert to scanable form */
      sc_format(buf, name, 0); name = buf; }
    fputs(name, out); fputc(' ', out);
  }                             /* print the item names */
  fputs(" (", out);             /* print rel. and abs. support */
  if (flags & OF_REL) { fprintf(out, fmt, (supp/(double)tacnt) *100);
                        fputs((flags & OF_ABS) ? "%/" : "%", out); }
  if (flags & OF_ABS) { fprintf(out, "%d", supp); }
  if (flags & OF_DEV) { fputs(", ", out); fprintf(out, fmt, dev); }
  fputs(")\n", out);            /* terminate the support output */
  return 1;                     /* return 'reported 1 item set' */
}  /* _report() */

/*----------------------------------------------------------------------
  Main Functions
----------------------------------------------------------------------*/

static void error (int code, ...)
{                               /* --- print an error message */
  #ifndef QUIET                 /* if not quiet version */
  va_list    args;              /* list of variable arguments */
  const char *msg;              /* error message */

  assert(prgname);              /* check the program name */
  if (code < E_UNKNOWN) code = E_UNKNOWN;
  if (code < 0) {               /* if to report an error, */
    msg = errmsgs[-code];       /* get the error message */
    if (!msg) msg = errmsgs[-E_UNKNOWN];
    fprintf(stderr, "\n%s: ", prgname);
    va_start(args, code);       /* get variable arguments */
    vfprintf(stderr, msg, args);/* print error message */
    va_end(args);               /* end argument evaluation */
  }
  #endif
  #ifndef NDEBUG                /* if debug version */
  if (fptree)  fpt_delete(fptree);    /* clean up memory */
  if (taset)   tas_delete(taset, 0);  /* and close files */
  if (itemset) is_delete(itemset);
  if (in  && (in  != stdin))  fclose(in);
  if (out && (out != stdout)) fclose(out);
  #endif
  #ifdef STORAGE                /* if storage debugging */
  showmem("at end of program"); /* check memory usage */
  #endif
  exit(code);                   /* abort the program */
}  /* error() */

/*--------------------------------------------------------------------*/

int main (int argc, char *argv[])
{                               /* --- main function */
  int     i, k = 0, n;          /* loop variables, counters */
  char    *s;                   /* to traverse the options */
  char    **optarg = NULL;      /* option argument */
  char    *fn_in   = NULL;      /* name of input  file */
  char    *fn_out  = NULL;      /* name of output file */
  char    *blanks  = NULL;      /* blanks */
  char    *fldseps = NULL;      /* field  separators */
  char    *recseps = NULL;      /* record separators */
  char    *cominds = NULL;      /* comment indicators */
  double  supp     = 0.1;       /* minimal support (in percent) */
  int     min      =  1;        /* minimal size of item set */
  int     max      =  5;        /* maximal size of item set */
  int     sort     = -2;        /* flag for item sorting and recoding */
  int     mode     = FPT_BONSAI;/* tree projection mode */
  int     heap     =  1;        /* flag for heap sort vs. quick sort */