[LUCENE-6654] KNearestNeighborClassifier not taking in consideration Class ranking

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 5.2.1
• Fix Version/s: 5.3, 6.0
• Component/s: modules/classification
• Labels: classification knn
• Lucene Fields: Patch Available
• Assignee: Tommaso Teofili
• Reporter: Alessandro Benedetti
• Created: 02/Jul/15 13:10
• Updated: 28/Aug/22 14:38
• Resolved: 03/Aug/15 14:05

Description

Currently the KNN Classifier assign the score for a ClassificationResult, based only on the frequency of the class in the top K results.

This is conceptually a simplification.
Actually the ranking must take a part.

If not this can happen :

Top 4
1) Class1
2) Class1
3) Class2
4) Class2

As a result of this Top 4 , both the classes will have the same score.
But the expected result is that Class1 has a better score, as the MLT score the documents accordingly.