-/*
- * $Id: relevance.c,v 1.2 2006-12-20 22:18:33 adam Exp $
- */
+/* This file is part of Pazpar2.
+ Copyright (C) 2006-2008 Index Data
+
+Pazpar2 is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+Pazpar2 is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+*/
+
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
#include <ctype.h>
#include <math.h>
#include "relevance.h"
#include "pazpar2.h"
+#define USE_TRIE 0
+
struct relevance
{
int *doc_frequency_vec;
int vec_len;
+#if USE_TRIE
struct word_trie *wt;
+#else
+ struct word_entry *entries;
+ pp2_charset_t pct;
+#endif
NMEM nmem;
};
+#if USE_TRIE
+#define raw_char(c) (((c) >= 'a' && (c) <= 'z') ? (c) - 'a' : -1)
+
+
// We use this data structure to recognize terms in input records,
// and map them to record term vectors for counting.
struct word_trie
static void word_trie_addterm(NMEM nmem, struct word_trie *n, const char *term, int num)
{
+
while (*term) {
int c = tolower(*term);
if (c < 'a' || c > 'z')
}
}
-#define raw_char(c) (((c) >= 'a' && (c) <= 'z') ? (c) - 'a' : -1)
-
-static int word_trie_match(struct word_trie *t, const char *word, int len, int *skipped)
+static int word_trie_match(struct word_trie *t, const char *word, int *skipped)
{
int c = raw_char(tolower(*word));
- if (!len)
+ if (!*word)
return 0;
- word++; len--;
+ word++;
(*skipped)++;
- if (!len || raw_char(*word) < 0)
+ if (!*word || raw_char(*word) < 0)
{
if (t->list[c].termno > 0)
return t->list[c].termno;
{
if (t->list[c].child)
{
- return word_trie_match(t->list[c].child, word, len, skipped);
+ return word_trie_match(t->list[c].child, word, skipped);
}
else
return 0;
return res;
}
-struct relevance *relevance_create(NMEM nmem, const char **terms, int numrecs)
+
+// FIXME. The definition of a word is crude here.. should support
+// some form of localization mechanism?
+void relevance_countwords(struct relevance *r, struct record_cluster *cluster,
+ const char *words, int multiplier)
+{
+ while (*words)
+ {
+ char c;
+ int res;
+ int skipped = 0;
+ while (*words && (c = raw_char(tolower(*words))) < 0)
+ words++;
+ if (!*words)
+ break;
+ res = word_trie_match(r->wt, words, &skipped);
+ if (res)
+ {
+ words += skipped;
+ cluster->term_frequency_vec[res] += multiplier;
+ }
+ else
+ {
+ while (*words && (c = raw_char(tolower(*words))) >= 0)
+ words++;
+ }
+ cluster->term_frequency_vec[0]++;
+ }
+}
+
+#else
+
+struct word_entry {
+ const char *norm_str;
+ int termno;
+ struct word_entry *next;
+};
+
+static void add_word_entry(NMEM nmem,
+ struct word_entry **entries,
+ const char *norm_str,
+ int term_no)
+{
+ struct word_entry *ne = nmem_malloc(nmem, sizeof(*ne));
+ ne->norm_str = nmem_strdup(nmem, norm_str);
+ ne->termno = term_no;
+
+ ne->next = *entries;
+ *entries = ne;
+}
+
+
+int word_entry_match(struct word_entry *entries, const char *norm_str)
+{
+ for (; entries; entries = entries->next)
+ {
+ if (!strcmp(norm_str, entries->norm_str))
+ return entries->termno;
+ }
+ return 0;
+}
+
+static struct word_entry *build_word_entries(pp2_charset_t pct, NMEM nmem,
+ const char **terms)
+{
+ int termno = 1; /* >0 signals THERE is an entry */
+ struct word_entry *entries = 0;
+ const char **p = terms;
+
+ for (; *p; p++)
+ {
+ pp2_relevance_token_t prt = pp2_relevance_tokenize(pct, *p);
+ const char *norm_str;
+
+ while ((norm_str = pp2_relevance_token_next(prt)))
+ add_word_entry(nmem, &entries, norm_str, termno);
+
+ pp2_relevance_token_destroy(prt);
+
+ termno++;
+ }
+ return entries;
+}
+
+void relevance_countwords(struct relevance *r, struct record_cluster *cluster,
+ const char *words, int multiplier)
+{
+ pp2_relevance_token_t prt = pp2_relevance_tokenize(r->pct, words);
+
+ const char *norm_str;
+
+ while ((norm_str = pp2_relevance_token_next(prt)))
+ {
+ int res = word_entry_match(r->entries, norm_str);
+ if (res)
+ cluster->term_frequency_vec[res] += multiplier;
+ cluster->term_frequency_vec[0]++;
+ }
+ pp2_relevance_token_destroy(prt);
+}
+
+#endif
+
+
+
+struct relevance *relevance_create(pp2_charset_t pct,
+ NMEM nmem, const char **terms, int numrecs)
{
struct relevance *res = nmem_malloc(nmem, sizeof(struct relevance));
const char **p;
;
res->vec_len = ++i;
res->doc_frequency_vec = nmem_malloc(nmem, res->vec_len * sizeof(int));
- bzero(res->doc_frequency_vec, res->vec_len * sizeof(int));
+ memset(res->doc_frequency_vec, 0, res->vec_len * sizeof(int));
res->nmem = nmem;
+#if USE_TRIE
res->wt = build_word_trie(nmem, terms);
+#else
+ res->entries = build_word_entries(pct, nmem, terms);
+ res->pct = pct;
+#endif
return res;
}
-void relevance_newrec(struct relevance *r, struct record *rec)
+void relevance_newrec(struct relevance *r, struct record_cluster *rec)
{
if (!rec->term_frequency_vec)
{
rec->term_frequency_vec = nmem_malloc(r->nmem, r->vec_len * sizeof(int));
- bzero(rec->term_frequency_vec, r->vec_len * sizeof(int));
+ memset(rec->term_frequency_vec, 0, r->vec_len * sizeof(int));
}
}
-// FIXME. The definition of a word is crude here.. should support
-// some form of localization mechanism?
-void relevance_countwords(struct relevance *r, struct record *head,
- const char *words, int len, int multiplier)
-{
- while (len)
- {
- char c;
- int res;
- int skipped;
- while (len && (c = raw_char(tolower(*words))) < 0)
- {
- words++;
- len--;
- }
- if (!len)
- return;
- skipped = 0;
- if ((res = word_trie_match(r->wt, words, len, &skipped)))
- {
- words += skipped;
- len -= skipped;
- head->term_frequency_vec[res] += multiplier;
- }
- else
- {
- while (len && (c = raw_char(tolower(*words))) >= 0)
- {
- words++;
- len--;
- }
- }
- head->term_frequency_vec[0]++;
- }
-}
-
-void relevance_donerecord(struct relevance *r, struct record *head)
+void relevance_donerecord(struct relevance *r, struct record_cluster *cluster)
{
int i;
for (i = 1; i < r->vec_len; i++)
- if (head->term_frequency_vec[i] > 0)
+ if (cluster->term_frequency_vec[i] > 0)
r->doc_frequency_vec[i]++;
r->doc_frequency_vec[0]++;
}
-#ifdef FLOAT_REL
-static int comp(const void *p1, const void *p2)
-{
- float res;
- struct record **r1 = (struct record **) p1;
- struct record **r2 = (struct record **) p2;
- res = (*r2)->relevance - (*r1)->relevance;
- if (res > 0)
- return 1;
- else if (res < 0)
- return -1;
- else
- return 0;
-}
-#else
-static int comp(const void *p1, const void *p2)
-{
- struct record **r1 = (struct record **) p1;
- struct record **r2 = (struct record **) p2;
- return (*r2)->relevance - (*r1)->relevance;
-}
-#endif
-
-// Prepare for a relevance-sorted read of up to num entries
+// Prepare for a relevance-sorted read
void relevance_prepare_read(struct relevance *rel, struct reclist *reclist)
{
int i;
if (!rel->doc_frequency_vec[i])
idfvec[i] = 0;
else
- idfvec[i] = log((float) rel->doc_frequency_vec[0] / rel->doc_frequency_vec[i]);
+ {
+ // This conditional may be terribly wrong
+ // It was there to address the situation where vec[0] == vec[i]
+ // which leads to idfvec[i] == 0... not sure about this
+ // Traditional TF-IDF may assume that a word that occurs in every
+ // record is irrelevant, but this is actually something we will
+ // see a lot
+ if ((idfvec[i] = log((float) rel->doc_frequency_vec[0] /
+ rel->doc_frequency_vec[i])) < 0.0000001)
+ idfvec[i] = 1;
+ }
}
// Calculate relevance for each document
for (i = 0; i < reclist->num_records; i++)
{
int t;
- struct record *rec = reclist->flatlist[i];
+ struct record_cluster *rec = reclist->flatlist[i];
float relevance;
relevance = 0;
for (t = 1; t < rel->vec_len; t++)
}
rec->relevance = (int) (relevance * 100000);
}
- qsort(reclist->flatlist, reclist->num_records, sizeof(struct record*), comp);
reclist->pointer = 0;
xfree(idfvec);
}
projects / pazpar2-moved-to-github.git / blobdiff