For in-stock items, allow specification of source and destination ite…

…ms separately.

macros/recommender_alternatives.pig

@@ -127,11 +127,12 @@ define recsys__GetItemItemRecommendations_DiversifyItemItem(user_item_signals, m
  * 
  * Input:
  *      user_item_signals: { (user:chararray, item:chararray, weight:float) }
- *      available_items: { (item:chararray) }
+ *      source_items: { (item:chararray) }
+ *      dest_items: { (item:chararray) }
  * Output:
  *      item_item_recs: { (item_A:chararray, item_B:chararray, weight:float, raw_weight:float, rank:int) }
  */
-define recsys__GetItemItemRecommendations_WithAvailableItems(user_item_signals, available_items) returns item_item_recs {
+define recsys__GetItemItemRecommendations_WithAvailableItems(user_item_signals, source_items, dest_items) returns item_item_recs {
 
     -- Convert user_item_signals to an item_item_graph
     ii_links_raw, item_weights   =   recsys__BuildItemItemGraph(
@@ -153,7 +154,8 @@ define recsys__GetItemItemRecommendations_WithAvailableItems(user_item_signals,
       -- calls different macro from standard recsys code
     $item_item_recs =  recsys__BuildItemItemRecommendationsFromGraph_withAvailableItems(
                            ii_links,
-                           $available_items, -- Added on to represent items in stock or not
+                           $source_items, -- Items that should have recommendations generated for them
+                           $dest_items, --Items that can be recommended
                            $NUM_RECS_PER_ITEM, 
                            $NUM_RECS_PER_ITEM
                        );

macros/recsys_alternatives.pig

@@ -85,23 +85,26 @@ returns item_recs {
 /*
  * This is an alternative of recsys__BuildItemItemRecommendationsFromGraph.  
  *
- * This takes an additional input of a set of available items to handle the case where not every
- * item is in stock or needs a recommendation; but the links to those items may still be valuable
- * in the shortest paths traversal.
+ * This takes an additional input of a set of available source items and available destination
+ * items, to handle the case where not every item is in stock or needs a recommendation; but the
+ * links to those items may still be valuable in the shortest paths traversal and when linking
+ * back to users.
  *
  * Input:
  *      Same inputs as recsys__BuildItemItemRecommendationsFromGraph.
- *      available_items: { (item:chararray) }
+ *      source_items: { (item:chararray) }
+ *      dest_items: { (item:chararray) }
  *
  * Output:
  *      Same output as recsys__BuildItemItemRecommendationsFromGraph.
  */
 define recsys__BuildItemItemRecommendationsFromGraph_withAvailableItems(
-                            ii_links, available_items, initial_nhood_size, num_recs)
+                            ii_links, source_items, dest_items, initial_nhood_size, num_recs)
 returns item_recs {
 
     graph, paths        =   recsys__InitShortestPaths_FromAvailableItems($ii_links,
-                                                                      $available_items,
+                                                                      $source_items,
+                                                                      $dest_items,
                                                                       $initial_nhood_size);
 
     two_step_terms      =   foreach (join graph by item_B, paths by item_A) generate
@@ -138,14 +141,15 @@ returns item_recs {
  * 
  * Input:
  *      ii_links: { (item_A:chararray, item_B:chararray, weight:float, raw_weight:float) }
- *      available_items: { (item:chararray) }
+ *      source_items: { (item:chararray) }
+ *      dest_items: { (item:chararray) }
  *      num_recs: int
  *
  * Output:
  *       graph: { (item_A:chararray, item_B:chararray, dist:float, raw_weight:float) }
  *       paths: { (item_A:chararray, item_B:chararray, dist:float, raw_weight:float) }
  */
-define recsys__InitShortestPaths_FromAvailableItems(ii_links, available_items, num_recs)
+define recsys__InitShortestPaths_FromAvailableItems(ii_links, source_items, dest_items, num_recs)
 returns graph, paths {
 
     distance_mat        =   foreach $ii_links generate
@@ -158,7 +162,7 @@ returns graph, paths {
                                       as (item_A, item_B, dist, raw_weight);
                             }
 
-    $graph              =   foreach (join $available_items by item, graph_tmp by item_A) generate
+    $graph              =   foreach (join $source_items by item, graph_tmp by item_A) generate
                                 item_A as item_A, item_B as item_B,
                                 dist as dist, raw_weight as raw_weight;
 
@@ -168,11 +172,11 @@ returns graph, paths {
     self_loops          =   foreach dest_verts generate
                                 id as item_A, id as item_B, 0.0f as dist, null as raw_weight;
     raw_paths           =   union graph_copy, self_loops;
-    $paths              =   foreach (join raw_paths by item_B, $available_items by item) generate
+    $paths              =   foreach (join raw_paths by item_B, $dest_items by item) generate
                                 raw_paths::item_A as item_A, 
                                 raw_paths::dist as dist,
                                 raw_paths::raw_weight as raw_weight,
-                                available_items::item as item_B; 
+                                raw_paths::item_B as item_B;
 };
 
 

pigscripts/techniques/in-stock-technique.pig

@@ -63,7 +63,7 @@ available_items = foreach (filter inventory_input by stock > 0) generate
 /******* Use Mortar recommendation engine to convert signals to recommendations **********/
 
 -- Use of non standard Mortar Recommendation engine macro
-item_item_recs = recsys__GetItemItemRecommendations_WithAvailableItems(user_signals, available_items);
+item_item_recs = recsys__GetItemItemRecommendations_WithAvailableItems(user_signals, available_items, available_items);
 user_item_recs = recsys__GetUserItemRecommendations(user_signals, item_item_recs);