Example usage for org.apache.lucene.search.similarities BM25Similarity getB

Introduction

In this page you can find the example usage for org.apache.lucene.search.similarities BM25Similarity getB.

Prototype

public final float getB() 

Source Link

Document

Returns the b parameter

Usage

From source file:org.apache.solr.search.similarities.TestBM25SimilarityFactory.java

License:Apache License

/** bm25 with parameters */
public void testParameters() throws Exception {
    Similarity sim = getSimilarity("text_params");
    assertEquals(BM25Similarity.class, sim.getClass());
    BM25Similarity bm25 = (BM25Similarity) sim;
    assertEquals(1.2f, bm25.getK1(), 0.01f);
    assertEquals(0.76f, bm25.getB(), 0.01f);
}

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From source file:org.elasticsearch.index.similarity.SimilarityTests.java

License:Apache License

@Test
public void testResolveSimilaritiesFromMapping_bm25() throws IOException {
    String mapping = XContentFactory.jsonBuilder().startObject().startObject("type").startObject("properties")
            .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
            .endObject().endObject().endObject().string();

    Settings indexSettings = ImmutableSettings.settingsBuilder()
            .put("index.similarity.my_similarity.type", "BM25").put("index.similarity.my_similarity.k1", 2.0f)
            .put("index.similarity.my_similarity.b", 1.5f)
            .put("index.similarity.my_similarity.discount_overlaps", false).build();
    SimilarityService similarityService = similarityService(indexSettings);
    DocumentMapper documentMapper = similarityService.mapperService().documentMapperParser().parse(mapping);
    assertThat(documentMapper.mappers().name("field1").mapper().similarity(),
            instanceOf(BM25SimilarityProvider.class));

    BM25Similarity similarity = (BM25Similarity) documentMapper.mappers().name("field1").mapper().similarity()
            .get();//from   w w  w . j  a  va  2s . c  o m
    assertThat(similarity.getK1(), equalTo(2.0f));
    assertThat(similarity.getB(), equalTo(1.5f));
    assertThat(similarity.getDiscountOverlaps(), equalTo(false));
}

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