New rank tweaks: follow, lead, length

Rank tweak: follow=number will increase mult by number if two terms
occur next to each other; number-1 if they are one term apart , .. 0
if they are number a part (all in order). Default is 0 (following
terms has no effect).

Rank tweak: lead=number will increase mult by number if term is first
term in field, number-1 if second, ... 0 if term is at offset
number of more. Default value is 0 (position irrelevant).

Rank tweak: length=strategy. length="linear" if mult is to be divided
by length (existing, default behavior), length="log" if mult is to be
divided by log2(1+length), length="none" if mult is not to be affected
by length.

diff --git a/NEWS b/NEWS
index d9165e8..0611b78 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,18 @@
+
+Rank tweak: follow=number will increase mult by number if two terms
+occur next to each other; number-1 if they are one term apart , .. 0
+if they are number a part (all in order). Default is 0 (following
+terms has no effect).
+
+Rank tweak: lead=number will increase mult by number if term is first
+term in field, number-1 if second, ... 0 if term is at offset
+number of more. Default value is 0 (position irrelevant).
+
+Rank tweak: length=strategy. length="linear" if mult is to be divided
+by length (existing, default behavior), length="log" if mult is to be 
+divided by log2(1+length), length="none" if mult is not to be affected
+by length.
+
 --- 1.6.20 2012/09/21
 
 Rank algorithm details may be printed as part of show reseponse in

diff --git a/src/client.c b/src/client.c
index b85195f..00d92ad 100644 (file)
--- a/src/client.c
+++ b/src/client.c
@@ -1311,7 +1311,10 @@ int client_parse_query(struct client *cl, const char *query,
     {
         // Initialize relevance structure with query terms
         se->relevance = relevance_create_ccl(se->service->charsets, cn,
-                                             se->service->rank_cluster);
+                                             se->service->rank_cluster,
+                                             se->service->rank_follow,
+                                             se->service->rank_lead,
+                                             se->service->rank_length);
     }
     ccl_rpn_delete(cn);
     return ret_value;

diff --git a/src/pazpar2_config.c b/src/pazpar2_config.c
index 00e36a6..73176b8 100644 (file)
--- a/src/pazpar2_config.c
+++ b/src/pazpar2_config.c
@@ -134,6 +134,9 @@ struct conf_service *service_init(struct conf_server *server,
     service->z3950_operation_timeout = 30;
     service->rank_cluster = 1;
     service->rank_debug = 0;
+    service->rank_follow = 0;
+    service->rank_lead = 0;
+    service->rank_length = 2;
 
     service->charsets = 0;
 
@@ -622,6 +625,9 @@ static struct conf_service *service_create_static(struct conf_server *server,
         {
             char *rank_cluster = (char *) xmlGetProp(n, (xmlChar *) "cluster");
             char *rank_debug = (char *) xmlGetProp(n, (xmlChar *) "debug");
+            char *rank_follow = (char *) xmlGetProp(n, (xmlChar *) "follow");
+            char *rank_lead = (char *) xmlGetProp(n, (xmlChar *) "lead");
+            char *rank_length= (char *) xmlGetProp(n, (xmlChar *) "length");
             if (rank_cluster)
             {
                 if (!strcmp(rank_cluster, "yes"))
@@ -646,8 +652,33 @@ static struct conf_service *service_create_static(struct conf_server *server,
                     return 0;
                 }
             }
+            if (rank_follow)
+            {
+                service->rank_follow = atoi(rank_follow);
+            }
+            if (rank_lead)
+            {
+                service->rank_lead = atoi(rank_lead);
+            }
+            if (rank_length)
+            {
+                if (!strcmp(rank_length, "linear"))
+                    service->rank_length = 2;
+                else if (!strcmp(rank_length, "log"))
+                    service->rank_length = 1; 
+                else if (!strcmp(rank_length, "none"))
+                    service->rank_length = 0;
+                else
+                {
+                    yaz_log(YLOG_FATAL, "service: rank@length linear|log|none");
+                    return 0;
+                }
+            }
             xmlFree(rank_cluster);
             xmlFree(rank_debug);
+            xmlFree(rank_follow);
+            xmlFree(rank_lead);
+            xmlFree(rank_length);
         }
         else if (!strcmp((const char *) n->name, "sort-default"))
         {

diff --git a/src/pazpar2_config.h b/src/pazpar2_config.h
index 8f80f39..af416a7 100644 (file)
--- a/src/pazpar2_config.h
+++ b/src/pazpar2_config.h
@@ -118,6 +118,9 @@ struct conf_service
     int z3950_operation_timeout;
     int rank_cluster;
     int rank_debug;
+    int rank_follow;
+    int rank_lead;
+    int rank_length;
     char *default_sort;
 
     int ref_count;

diff --git a/src/record.h b/src/record.h
index a5afde1..fb6f8e1 100644 (file)
--- a/src/record.h
+++ b/src/record.h
@@ -84,7 +84,6 @@ struct record_cluster
     char *merge_key;
     int relevance_score;
     int *term_frequency_vec;
-    int *term_frequency_vec_tmp;
     float *term_frequency_vecf;
     // Set-specific ID for this record
     char *recid;

diff --git a/src/relevance.c b/src/relevance.c
index 3755b09..a002a7b 100644 (file)
--- a/src/relevance.c
+++ b/src/relevance.c
@@ -31,10 +31,14 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 struct relevance
 {
     int *doc_frequency_vec;
+    int *term_frequency_vec_tmp;
     int vec_len;
     struct word_entry *entries;
     pp2_charset_token_t prt;
     int rank_cluster;
+    int follow_boost;
+    int lead_boost;
+    int length_divide;
     NMEM nmem;
 };
 
@@ -42,17 +46,22 @@ struct word_entry {
     const char *norm_str;
     const char *display_str;
     int termno;
+    int follow_boost;
     char *ccl_field;
     struct word_entry *next;
 };
 
-static int word_entry_match(struct word_entry *entries, const char *norm_str,
+static int word_entry_match(struct relevance *r, const char *norm_str,
                             const char *rank, int *mult)
 {
-    for (; entries; entries = entries->next)
+    int i = 1;
+    struct word_entry *entries = r->entries;
+    for (; entries; entries = entries->next, i++)
     {
         if (*norm_str && !strcmp(norm_str, entries->norm_str))
         {
+            int extra = r->follow_boost;
+            struct word_entry *e_follow = entries;
             const char *cp = 0;
             int no_read = 0;
             sscanf(rank, "%d%n", mult, &no_read);
@@ -65,8 +74,14 @@ static int word_entry_match(struct word_entry *entries, const char *norm_str,
                     memcmp(entries->ccl_field, rank, cp - rank) == 0)
                     *mult = atoi(cp + 1);
             }
+            (*mult) += entries->follow_boost;
+            while ((e_follow = e_follow->next) != 0 && extra > 0)
+            {
+                e_follow->follow_boost = extra--;
+            }
             return entries->termno;
         }
+        entries->follow_boost = 0;
     }
     return 0;
 }
@@ -75,39 +90,57 @@ void relevance_countwords(struct relevance *r, struct record_cluster *cluster,
                           const char *words, const char *rank,
                           const char *name)
 {
-    int *mult = cluster->term_frequency_vec_tmp;
+    int *mult = r->term_frequency_vec_tmp;
     const char *norm_str;
     int i, length = 0;
-    struct word_entry *e = r->entries;
+    int lead_mult = r->lead_boost;
+    struct word_entry *e;
     WRBUF w = cluster->relevance_explain1;
 
     pp2_charset_token_first(r->prt, words, 0);
-    for (i = 1; i < r->vec_len; i++)
+    for (e = r->entries, i = 1; i < r->vec_len; i++, e = e->next)
+    {
         mult[i] = 0;
+        e->follow_boost = 0;
+    }
 
     assert(rank);
     while ((norm_str = pp2_charset_token_next(r->prt)))
     {
         int local_mult = 0;
-        int res = word_entry_match(r->entries, norm_str, rank, &local_mult);
+        int res = word_entry_match(r, norm_str, rank, &local_mult);
         if (res)
         {
             assert(res < r->vec_len);
-            mult[res] += local_mult;
+            mult[res] += local_mult + lead_mult;
         }
+        if (lead_mult > 0)
+            --lead_mult;
         length++;
     }
 
-    for (i = 1; i < r->vec_len; i++)
+    for (e = r->entries, i = 1; i < r->vec_len; i++, e = e->next)
     {
-        if (length > 0 && mult[i] > 0) /* only add if non-empty */
+        if (length == 0 || mult[i] == 0)
+            continue;
+        wrbuf_printf(w, "%s: field=%s vecf[%d] += mult(%d)",
+                     e->display_str, name, i, mult[i]);
+        switch (r->length_divide)
         {
-            wrbuf_printf(w, "%s: field=%s vecf[%d] += mult(%d) / length(%d);\n",
-                         e->display_str, name, i, mult[i], length);
+        case 0:
+            wrbuf_printf(w, ";\n");
+            cluster->term_frequency_vecf[i] += (double) mult[i];
+            break;
+        case 1:
+            wrbuf_printf(w, " / log2(1+length(%d));\n", length);
+            cluster->term_frequency_vecf[i] +=
+                (double) mult[i] / log2(1 + length);
+            break;
+        case 2:
+            wrbuf_printf(w, " / length(%d);\n", length);
             cluster->term_frequency_vecf[i] += (double) mult[i] / length;
         }
         cluster->term_frequency_vec[i] += mult[i];
-        e = e->next;
     }
 
     cluster->term_frequency_vec[0] += length;
@@ -159,7 +192,9 @@ static void pull_terms(struct relevance *res, struct ccl_rpn_node *n)
 
 struct relevance *relevance_create_ccl(pp2_charset_fact_t pft,
                                        struct ccl_rpn_node *query,
-                                       int rank_cluster)
+                                       int rank_cluster,
+                                       int follow_boost, int lead_boost,
+                                       int length_divide)
 {
     NMEM nmem = nmem_create();
     struct relevance *res = nmem_malloc(nmem, sizeof(*res));
@@ -169,6 +204,9 @@ struct relevance *relevance_create_ccl(pp2_charset_fact_t pft,
     res->entries = 0;
     res->vec_len = 1;
     res->rank_cluster = rank_cluster;
+    res->follow_boost = follow_boost;
+    res->lead_boost = lead_boost;
+    res->length_divide = length_divide;
     res->prt = pp2_charset_token_create(pft, "relevance");
 
     pull_terms(res, query);
@@ -176,6 +214,11 @@ struct relevance *relevance_create_ccl(pp2_charset_fact_t pft,
     res->doc_frequency_vec = nmem_malloc(nmem, res->vec_len * sizeof(int));
     for (i = 0; i < res->vec_len; i++)
         res->doc_frequency_vec[i] = 0;
+
+    // worker array
+    res->term_frequency_vec_tmp =
+        nmem_malloc(res->nmem,
+                    res->vec_len * sizeof(*res->term_frequency_vec_tmp));
     return res;
 }
 
@@ -208,11 +251,6 @@ void relevance_newrec(struct relevance *r, struct record_cluster *rec)
                         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));
     }
 }
 

diff --git a/src/relevance.h b/src/relevance.h
index c2ffa4a..f585899 100644 (file)
--- a/src/relevance.h
+++ b/src/relevance.h
@@ -30,7 +30,8 @@ struct reclist;
 
 struct relevance *relevance_create_ccl(pp2_charset_fact_t pft,
                                        struct ccl_rpn_node *query,
-                                       int rank_cluster);
+                                       int rank_cluster, int follow_boost,
+                                       int lead_boost, int length_divide);
 void relevance_destroy(struct relevance **rp);
 void relevance_newrec(struct relevance *r, struct record_cluster *cluster);
 void relevance_countwords(struct relevance *r, struct record_cluster *cluster,