org.elasticsearch.index.similarity.BM25SimilarityProvider Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you under
* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.elasticsearch.index.similarity;
import org.apache.lucene.search.similarities.BM25Similarity;
import org.apache.lucene.search.similarities.Similarity;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.inject.assistedinject.Assisted;
import org.elasticsearch.common.settings.Settings;
/**
* {@link SimilarityProvider} for the {@link BM25Similarity}.
*
* Configuration options available:
*
* - k1
* - b
* - discount_overlaps
*
* @see BM25Similarity For more information about configuration
*/
public class BM25SimilarityProvider extends AbstractSimilarityProvider {
private final BM25Similarity similarity;
@Inject
public BM25SimilarityProvider(@Assisted String name, @Assisted Settings settings) {
super(name);
float k1 = settings.getAsFloat("k1", 1.2f);
float b = settings.getAsFloat("b", 0.75f);
boolean discountOverlaps = settings.getAsBoolean("discount_overlaps", true);
this.similarity = new BM25Similarity(k1, b);
this.similarity.setDiscountOverlaps(discountOverlaps);
}
/**
* {@inheritDoc}
*/
@Override
public Similarity get() {
return similarity;
}
}