alessandrobenedetti commented on code in PR #926:
URL: https://github.com/apache/lucene/pull/926#discussion_r885637733


##########
lucene/core/src/java/org/apache/lucene/index/VectorSimilarityFunction.java:
##########
@@ -47,63 +42,30 @@ public float convertToScore(float similarity) {
   DOT_PRODUCT {
     @Override
     public float compare(float[] v1, float[] v2) {
-      return dotProduct(v1, v2);
-    }
-
-    @Override
-    public float convertToScore(float similarity) {
-      return (1 + similarity) / 2;
+      return (1 + dotProduct(v1, v2)) / 2;
     }
   },
 
   /**
    * Cosine similarity. NOTE: the preferred way to perform cosine similarity 
is to normalize all
    * vectors to unit length, and instead use {@link 
VectorSimilarityFunction#DOT_PRODUCT}. You
    * should only use this function if you need to preserve the original 
vectors and cannot normalize
-   * them in advance.
+   * them in advance. The similarity score is normalised to assure it is 
positive.
    */
   COSINE {
     @Override
     public float compare(float[] v1, float[] v2) {
-      return cosine(v1, v2);
-    }
-
-    @Override
-    public float convertToScore(float similarity) {
-      return (1 + similarity) / 2;
+      return (1 + cosine(v1, v2)) / 2;
     }
   };
 
   /**
-   * If true, the scores associated with vector comparisons are nonnegative 
and in reverse order;
-   * that is, lower scores represent more similar vectors. Otherwise, if 
false, higher scores
-   * represent more similar vectors, and scores may be negative or positive.
-   */
-  public final boolean reversed;
-
-  VectorSimilarityFunction(boolean reversed) {
-    this.reversed = reversed;
-  }
-
-  VectorSimilarityFunction() {
-    reversed = false;
-  }
-
-  /**
-   * Calculates a similarity score between the two vectors with a specified 
function.
+   * Calculates a similarity score between the two vectors with a specified 
function. Higher
+   * similarity scores correspond to closer vectors.
    *
    * @param v1 a vector
    * @param v2 another vector, of the same dimension
    * @return the value of the similarity function applied to the two vectors
    */
   public abstract float compare(float[] v1, float[] v2);

Review Comment:
   Ok, not renaming that then, resolving the conversation!



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org
For additional commands, e-mail: issues-h...@lucene.apache.org

Reply via email to