org.elasticsearch.index.similarity.BM25SimilarityProvider Maven / Gradle / Ivy
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* the Apache License, Version 2.0 (the "License"); you may
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
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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;
}
}