add support for disabling idf using idf_weighting=0

bolcom · Mar 15, 2022 · 6f3127d · 6f3127d
1 parent 1357284
commit 6f3127d
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Showing 2 changed files with 9 additions and 7 deletions.
diff --git a/src/vmisknn/mod.rs b/src/vmisknn/mod.rs
@@ -143,8 +143,13 @@ pub fn predict<I: SimilarityComputationNew + Send + Sync>(
 
         for item_id in training_item_ids.iter() {
             let item_idf = index.idf(item_id);
-            *item_scores.entry(*item_id).or_insert(0.0) +=
-                session_weight * item_idf * scored_session.score;
+            if item_idf > 0.0 {
+                *item_scores.entry(*item_id).or_insert(0.0) +=
+                    session_weight * item_idf * scored_session.score;
+            } else {
+                *item_scores.entry(*item_id).or_insert(0.0) +=
+                    session_weight * scored_session.score;
+            }
         }
     }
 

diff --git a/src/vmisknn/vmis_index.rs b/src/vmisknn/vmis_index.rs
@@ -506,13 +506,10 @@ pub(crate) fn prepare_hashmap(
         item_to_top_sessions_ordered.insert(*current_item, current_item_similar_sessions_id_sorted);
         // Store (item, idf score) in second hashmap
         // let idf_score = (current_item_timestamps.len() as f64 / historical_sessions_values_sorted.len() as f64).ln();
-        let idf_score = if idf_weighting > 0.0 {
+        let idf_score =
             (historical_sessions_values_sorted.len() as f64
                 / current_item_timestamps.len() as f64)
-                .ln() * idf_weighting
-        } else {
-            1.0
-        };
+                .ln() * idf_weighting;
         item_to_idf_score.insert(*current_item, idf_score);
         let attributes = ProductAttributes {
             is_adult: false,