Example usage for org.apache.lucene.expressions Expression getDoubleValuesSource

Introduction

In this page you can find the example usage for org.apache.lucene.expressions Expression getDoubleValuesSource.

Prototype

public DoubleValuesSource getDoubleValuesSource(Bindings bindings) 

Source Link

Document

Get a DoubleValuesSource which can compute the value of this expression in the context of the given bindings.

Usage

From source file:com.czw.search.lucene.example.facet.DistanceFacetsExample.java

License:Apache License

private DoubleValuesSource getDistanceValueSource() {
    Expression distance;
    try {//  w  w w  .  j a  va  2 s . com
        distance = JavascriptCompiler
                .compile("haversin(" + ORIGIN_LATITUDE + "," + ORIGIN_LONGITUDE + ",latitude,longitude)");
    } catch (ParseException pe) {
        // Should not happen
        throw new RuntimeException(pe);
    }
    SimpleBindings bindings = new SimpleBindings();
    bindings.add(new SortField("latitude", SortField.Type.DOUBLE));
    bindings.add(new SortField("longitude", SortField.Type.DOUBLE));

    return distance.getDoubleValuesSource(bindings);
}

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From source file:com.czw.search.lucene.example.facet.ExpressionAggregationFacetsExample.java

License:Apache License

/** User runs a query and aggregates facets. */
private FacetResult search() throws IOException, ParseException {
    DirectoryReader indexReader = DirectoryReader.open(indexDir);
    IndexSearcher searcher = new IndexSearcher(indexReader);
    TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir);

    // Aggregate categories by an expression that combines the document's score
    // and its popularity field
    Expression expr = JavascriptCompiler.compile("_score * sqrt(popularity)");
    SimpleBindings bindings = new SimpleBindings();
    bindings.add(new SortField("_score", SortField.Type.SCORE)); // the score of the document
    bindings.add(new SortField("popularity", SortField.Type.LONG)); // the value of the 'popularity' field

    // Aggregates the facet values
    FacetsCollector fc = new FacetsCollector(true);

    // MatchAllDocsQuery is for "browsing" (counts facets
    // for all non-deleted docs in the index); normally
    // you'd use a "normal" query:
    FacetsCollector.search(searcher, new MatchAllDocsQuery(), 10, fc);

    // Retrieve results
    Facets facets = new TaxonomyFacetSumValueSource(taxoReader, config, fc,
            expr.getDoubleValuesSource(bindings));
    FacetResult result = facets.getTopChildren(10, "A");

    indexReader.close();//from  w ww  . j a va2 s  . c om
    taxoReader.close();

    return result;
}

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