1 /* This file is part of Pazpar2.
2 Copyright (C) 2006-2013 Index Data
4 Pazpar2 is free software; you can redistribute it and/or modify it under
5 the terms of the GNU General Public License as published by the Free
6 Software Foundation; either version 2, or (at your option) any later
9 Pazpar2 is distributed in the hope that it will be useful, but WITHOUT ANY
10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 #include "relevance.h"
32 #define log2(x) (log(x)/log(2))
37 int *doc_frequency_vec;
38 int *term_frequency_vec_tmp;
41 struct word_entry *entries;
42 pp2_charset_token_t prt;
52 const char *display_str;
55 struct word_entry *next;
58 static struct word_entry *word_entry_match(struct relevance *r,
60 const char *rank, int *weight)
63 struct word_entry *entries = r->entries;
64 for (; entries; entries = entries->next, i++)
66 if (*norm_str && !strcmp(norm_str, entries->norm_str))
70 sscanf(rank, "%d%n", weight, &no_read);
74 if (no_read > 0 && (cp = strchr(rank, ' ')))
76 if ((cp - rank) == strlen(entries->ccl_field) &&
77 memcmp(entries->ccl_field, rank, cp - rank) == 0)
78 *weight = atoi(cp + 1);
86 int relevance_snippet(struct relevance *r,
87 const char *words, const char *name,
94 pp2_charset_token_first(r->prt, words, 0);
95 while ((norm_str = pp2_charset_token_next(r->prt)))
97 size_t org_start, org_len;
98 struct word_entry *entries = r->entries;
101 pp2_get_org(r->prt, &org_start, &org_len);
102 for (; entries; entries = entries->next, i++)
104 if (*norm_str && !strcmp(norm_str, entries->norm_str))
110 wrbuf_puts(w_snippet, "<match>");
120 wrbuf_puts(w_snippet, "<match>");
129 wrbuf_puts(w_snippet, "</match>");
132 wrbuf_xmlputs_n(w_snippet, words + org_start, org_len);
135 wrbuf_puts(w_snippet, "</match>");
138 yaz_log(YLOG_DEBUG, "SNIPPET match: %s", wrbuf_cstr(w_snippet));
143 void relevance_countwords(struct relevance *r, struct record_cluster *cluster,
144 const char *words, const char *rank,
147 int *w = r->term_frequency_vec_tmp;
148 const char *norm_str;
150 double lead_decay = r->lead_decay;
151 struct word_entry *e;
152 WRBUF wr = cluster->relevance_explain1;
153 int printed_about_field = 0;
155 pp2_charset_token_first(r->prt, words, 0);
156 for (e = r->entries, i = 1; i < r->vec_len; i++, e = e->next)
163 while ((norm_str = pp2_charset_token_next(r->prt)))
165 int local_weight = 0;
166 e = word_entry_match(r, norm_str, rank, &local_weight);
172 if (!printed_about_field)
174 printed_about_field = 1;
175 wrbuf_printf(wr, "field=%s content=", name);
176 if (strlen(words) > 50)
178 wrbuf_xmlputs_n(wr, words, 49);
179 wrbuf_puts(wr, " ...");
182 wrbuf_xmlputs(wr, words);
183 wrbuf_puts(wr, ";\n");
185 assert(res < r->vec_len);
186 w[res] += local_weight / (1 + log2(1 + lead_decay * length));
187 wrbuf_printf(wr, "%s: w[%d] += w(%d) / "
188 "(1+log2(1+lead_decay(%f) * length(%d)));\n",
189 e->display_str, res, local_weight, lead_decay, length);
191 if (j > 0 && r->term_pos[j])
193 int d = length + 1 - r->term_pos[j];
194 wrbuf_printf(wr, "%s: w[%d] += w[%d](%d) * follow(%f) / "
196 e->display_str, res, res, w[res],
197 r->follow_factor, d);
198 w[res] += w[res] * r->follow_factor / (1 + log2(d));
200 for (j = 0; j < r->vec_len; j++)
201 r->term_pos[j] = j < res ? 0 : length + 1;
206 for (e = r->entries, i = 1; i < r->vec_len; i++, e = e->next)
208 if (length == 0 || w[i] == 0)
210 wrbuf_printf(wr, "%s: tf[%d] += w[%d](%d)", e->display_str, i, i, w[i]);
211 switch (r->length_divide)
214 cluster->term_frequency_vecf[i] += (double) w[i];
217 wrbuf_printf(wr, " / log2(1+length(%d))", length);
218 cluster->term_frequency_vecf[i] +=
219 (double) w[i] / log2(1 + length);
222 wrbuf_printf(wr, " / length(%d)", length);
223 cluster->term_frequency_vecf[i] += (double) w[i] / length;
225 cluster->term_frequency_vec[i] += w[i];
226 wrbuf_printf(wr, " (%f);\n", cluster->term_frequency_vecf[i]);
229 cluster->term_frequency_vec[0] += length;
232 static void pull_terms(struct relevance *res, struct ccl_rpn_node *n)
245 pull_terms(res, n->u.p[0]);
246 pull_terms(res, n->u.p[1]);
249 nmem_strsplit(res->nmem, " ", n->u.t.term, &words, &numwords);
250 for (i = 0; i < numwords; i++)
252 const char *norm_str;
254 ccl_field = nmem_strdup_null(res->nmem, n->u.t.qual);
256 pp2_charset_token_first(res->prt, words[i], 0);
257 while ((norm_str = pp2_charset_token_next(res->prt)))
259 struct word_entry **e = &res->entries;
262 *e = nmem_malloc(res->nmem, sizeof(**e));
263 (*e)->norm_str = nmem_strdup(res->nmem, norm_str);
264 (*e)->ccl_field = ccl_field;
265 (*e)->termno = res->vec_len++;
266 (*e)->display_str = nmem_strdup(res->nmem, words[i]);
275 void relevance_clear(struct relevance *r)
280 for (i = 0; i < r->vec_len; i++)
281 r->doc_frequency_vec[i] = 0;
285 struct relevance *relevance_create_ccl(pp2_charset_fact_t pft,
286 struct ccl_rpn_node *query,
288 double follow_factor, double lead_decay,
291 NMEM nmem = nmem_create();
292 struct relevance *res = nmem_malloc(nmem, sizeof(*res));
297 res->rank_cluster = rank_cluster;
298 res->follow_factor = follow_factor;
299 res->lead_decay = lead_decay;
300 res->length_divide = length_divide;
301 res->prt = pp2_charset_token_create(pft, "relevance");
303 pull_terms(res, query);
305 res->doc_frequency_vec = nmem_malloc(nmem, res->vec_len * sizeof(int));
308 res->term_frequency_vec_tmp =
309 nmem_malloc(res->nmem,
310 res->vec_len * sizeof(*res->term_frequency_vec_tmp));
313 nmem_malloc(res->nmem, res->vec_len * sizeof(*res->term_pos));
315 relevance_clear(res);
319 void relevance_destroy(struct relevance **rp)
323 pp2_charset_token_destroy((*rp)->prt);
324 nmem_destroy((*rp)->nmem);
329 void relevance_newrec(struct relevance *r, struct record_cluster *rec)
331 if (!rec->term_frequency_vec)
335 // term frequency [1,..] . [0] is total length of all fields
336 rec->term_frequency_vec =
338 r->vec_len * sizeof(*rec->term_frequency_vec));
339 for (i = 0; i < r->vec_len; i++)
340 rec->term_frequency_vec[i] = 0;
342 // term frequency divided by length of field [1,...]
343 rec->term_frequency_vecf =
345 r->vec_len * sizeof(*rec->term_frequency_vecf));
346 for (i = 0; i < r->vec_len; i++)
347 rec->term_frequency_vecf[i] = 0.0;
351 void relevance_donerecord(struct relevance *r, struct record_cluster *cluster)
355 for (i = 1; i < r->vec_len; i++)
356 if (cluster->term_frequency_vec[i] > 0)
357 r->doc_frequency_vec[i]++;
359 r->doc_frequency_vec[0]++;
362 // Prepare for a relevance-sorted read
363 void relevance_prepare_read(struct relevance *rel, struct reclist *reclist)
366 float *idfvec = xmalloc(rel->vec_len * sizeof(float));
368 reclist_enter(reclist);
369 // Calculate document frequency vector for each term.
370 for (i = 1; i < rel->vec_len; i++)
372 if (!rel->doc_frequency_vec[i])
376 /* add one to nominator idf(t,D) to ensure a value > 0 */
377 idfvec[i] = log((float) (1 + rel->doc_frequency_vec[0]) /
378 rel->doc_frequency_vec[i]);
381 // Calculate relevance for each document
386 struct word_entry *e = rel->entries;
387 struct record_cluster *rec = reclist_read_record(reclist);
390 w = rec->relevance_explain2;
392 wrbuf_puts(w, "relevance = 0;\n");
393 for (i = 1; i < rel->vec_len; i++)
395 float termfreq = (float) rec->term_frequency_vecf[i];
396 int add = 100000 * termfreq * idfvec[i];
398 wrbuf_printf(w, "idf[%d] = log(((1 + total(%d))/termoccur(%d));\n",
399 i, rel->doc_frequency_vec[0],
400 rel->doc_frequency_vec[i]);
401 wrbuf_printf(w, "%s: relevance += 100000 * tf[%d](%f) * "
402 "idf[%d](%f) (%d);\n",
403 e->display_str, i, termfreq, i, idfvec[i], add);
407 if (!rel->rank_cluster)
409 struct record *record;
410 int cluster_size = 0;
412 for (record = rec->records; record; record = record->next)
415 wrbuf_printf(w, "score = relevance(%d)/cluster_size(%d);\n",
416 relevance, cluster_size);
417 relevance /= cluster_size;
421 wrbuf_printf(w, "score = relevance(%d);\n", relevance);
423 rec->relevance_score = relevance;
425 reclist_leave(reclist);
432 * c-file-style: "Stroustrup"
433 * indent-tabs-mode: nil
435 * vim: shiftwidth=4 tabstop=8 expandtab