X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=src%2Frelevance.c;h=35b7d8312c040b677350d28a3485addcea460f7a;hb=e6d6362b750ae25591ee5a40e135878fd590e13e;hp=b1713e0b1969486b60b116249ce609bea3e6b46d;hpb=6590ecb69cda8c6e25fe137f0130996d2d1ccb9e;p=pazpar2-moved-to-github.git diff --git a/src/relevance.c b/src/relevance.c index b1713e0..35b7d83 100644 --- a/src/relevance.c +++ b/src/relevance.c @@ -1,117 +1,127 @@ -/* - * $Id: relevance.c,v 1.6 2007-01-08 19:39:12 quinn Exp $ - */ +/* This file is part of Pazpar2. + Copyright (C) 2006-2010 Index Data -#include -#include -#include +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 +#include #endif +#include +#include +#include + #include "relevance.h" -#include "pazpar2.h" +#include "session.h" struct relevance { int *doc_frequency_vec; int vec_len; - struct word_trie *wt; + struct word_entry *entries; + pp2_relevance_token_t prt; NMEM nmem; }; -// We use this data structure to recognize terms in input records, -// and map them to record term vectors for counting. -struct word_trie -{ - struct - { - struct word_trie *child; - int termno; - } list[26]; + +struct word_entry { + const char *norm_str; + int termno; + struct word_entry *next; }; -static struct word_trie *create_word_trie_node(NMEM nmem) +static void add_word_entry(NMEM nmem, + struct word_entry **entries, + const char *norm_str, + int term_no) { - struct word_trie *res = nmem_malloc(nmem, sizeof(struct word_trie)); - int i; - for (i = 0; i < 26; i++) + 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) { - res->list[i].child = 0; - res->list[i].termno = -1; + if (!strcmp(norm_str, entries->norm_str)) + return entries->termno; } - return res; + return 0; } -static void word_trie_addterm(NMEM nmem, struct word_trie *n, const char *term, int num) +static struct word_entry *build_word_entries(pp2_relevance_token_t prt, + NMEM nmem, + const char **terms) { - while (*term) { - int c = tolower(*term); - if (c < 'a' || c > 'z') - term++; - else - { - c -= 'a'; - if (!*(++term)) - n->list[c].termno = num; - else - { - if (!n->list[c].child) - { - struct word_trie *new = create_word_trie_node(nmem); - n->list[c].child = new; - } - word_trie_addterm(nmem, n->list[c].child, term, num); - } - break; - } + int termno = 1; /* >0 signals THERE is an entry */ + struct word_entry *entries = 0; + const char **p = terms; + + for (; *p; p++) + { + const char *norm_str; + + pp2_relevance_first(prt, *p, 0); + while ((norm_str = pp2_relevance_token_next(prt))) + add_word_entry(nmem, &entries, norm_str, termno); + termno++; } + return entries; } -#define raw_char(c) (((c) >= 'a' && (c) <= 'z') ? (c) - 'a' : -1) - -static int word_trie_match(struct word_trie *t, const char *word, int *skipped) +void relevance_countwords(struct relevance *r, struct record_cluster *cluster, + const char *words, int multiplier, const char *name) { - int c = raw_char(tolower(*word)); + int *mult = cluster->term_frequency_vec_tmp; + const char *norm_str; + int i, length = 0; - if (!*word) - return 0; + pp2_relevance_first(r->prt, words, 0); + for (i = 1; i < r->vec_len; i++) + mult[i] = 0; - word++; - (*skipped)++; - if (!*word || raw_char(*word) < 0) + while ((norm_str = pp2_relevance_token_next(r->prt))) { - if (t->list[c].termno > 0) - return t->list[c].termno; - else - return 0; - } - else - { - if (t->list[c].child) + int res = word_entry_match(r->entries, norm_str); + if (res) { - return word_trie_match(t->list[c].child, word, skipped); + assert(res < r->vec_len); + mult[res] += multiplier; } - else - return 0; + length++; } -} - - -static struct word_trie *build_word_trie(NMEM nmem, const char **terms) -{ - struct word_trie *res = create_word_trie_node(nmem); - const char **p; - int i; + for (i = 1; i < r->vec_len; i++) + { + if (length > 0) /* only add if non-empty */ + cluster->term_frequency_vecf[i] += (double) mult[i] / length; + cluster->term_frequency_vec[i] += mult[i]; + } - for (i = 1, p = terms; *p; p++, i++) - word_trie_addterm(nmem, res, *p, i); - return res; + cluster->term_frequency_vec[0] += length; } -struct relevance *relevance_create(NMEM nmem, const char **terms, int numrecs) +struct relevance *relevance_create(pp2_charset_t pct, + NMEM nmem, const char **terms) { struct relevance *res = nmem_malloc(nmem, sizeof(struct relevance)); const char **p; @@ -121,51 +131,50 @@ struct relevance *relevance_create(NMEM nmem, const char **terms, int numrecs) ; 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; - res->wt = build_word_trie(nmem, terms); + res->prt = pp2_relevance_tokenize(pct); + res->entries = build_word_entries(res->prt, nmem, terms); return res; } -void relevance_newrec(struct relevance *r, struct record_cluster *rec) +void relevance_destroy(struct relevance **rp) { - if (!rec->term_frequency_vec) + if (*rp) { - rec->term_frequency_vec = nmem_malloc(r->nmem, r->vec_len * sizeof(int)); - bzero(rec->term_frequency_vec, r->vec_len * sizeof(int)); + pp2_relevance_token_destroy((*rp)->prt); + *rp = 0; } } - -// 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) +void relevance_newrec(struct relevance *r, struct record_cluster *rec) { - while (*words) + if (!rec->term_frequency_vec) { - char c; - int res; - int skipped; - while (*words && (c = raw_char(tolower(*words))) < 0) - words++; - if (!*words) - return; - skipped = 0; - if ((res = word_trie_match(r->wt, words, &skipped))) - { - words += skipped; - cluster->term_frequency_vec[res] += multiplier; - } - else - { - while (*words && (c = raw_char(tolower(*words))) >= 0) - words++; - } - cluster->term_frequency_vec[0]++; + int i; + + // term frequency [1,..] . [0] is total length of all fields + rec->term_frequency_vec = + nmem_malloc(r->nmem, + r->vec_len * sizeof(*rec->term_frequency_vec)); + for (i = 0; i < r->vec_len; i++) + rec->term_frequency_vec[i] = 0; + + // term frequency divided by length of field [1,...] + rec->term_frequency_vecf = + nmem_malloc(r->nmem, + r->vec_len * sizeof(*rec->term_frequency_vecf)); + for (i = 0; i < r->vec_len; i++) + rec->term_frequency_vecf[i] = 0.0; + + // for relevance_countwords (so we don't have to xmalloc/xfree) + rec->term_frequency_vec_tmp = + nmem_malloc(r->nmem, + r->vec_len * sizeof(*rec->term_frequency_vec_tmp)); } } + void relevance_donerecord(struct relevance *r, struct record_cluster *cluster) { int i; @@ -177,69 +186,68 @@ void relevance_donerecord(struct relevance *r, struct record_cluster *cluster) 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_cluster **r1 = (struct record_cluster **) p1; - struct record_cluster **r2 = (struct record_cluster **) 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; float *idfvec = xmalloc(rel->vec_len * sizeof(float)); + reclist_enter(reclist); // Calculate document frequency vector for each term. for (i = 1; i < rel->vec_len; 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++) + + while (1) { int t; - struct record_cluster *rec = reclist->flatlist[i]; - float relevance; - relevance = 0; + int relevance = 0; + struct record_cluster *rec = reclist_read_record(reclist); + if (!rec) + break; for (t = 1; t < rel->vec_len; t++) { float termfreq; - if (!rec->term_frequency_vec[0]) - break; - termfreq = (float) rec->term_frequency_vec[t] / rec->term_frequency_vec[0]; - relevance += termfreq * idfvec[t]; +#if 1 + termfreq = (float) rec->term_frequency_vecf[t]; +#else + if (rec->term_frequency_vec[0]) + { + termfreq = (float) + rec->term_frequency_vec[t] / rec->term_frequency_vec[0] ; + } + else + termfreq = 0.0; +#endif + relevance += 100000 * (termfreq * idfvec[t] + 0.0000005); } - rec->relevance = (int) (relevance * 100000); + rec->relevance_score = relevance; } - qsort(reclist->flatlist, reclist->num_records, sizeof(struct record*), comp); - reclist->pointer = 0; + reclist_leave(reclist); xfree(idfvec); } /* * Local variables: * c-basic-offset: 4 + * c-file-style: "Stroustrup" * indent-tabs-mode: nil * End: * vim: shiftwidth=4 tabstop=8 expandtab */ +