/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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
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 * Unless required by applicable law or agreed to in writing, software
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package org.apache.lucene.queries.function.valuesource;

import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.queries.function.docvalues.FloatDocValues;
import org.apache.lucene.search.IndexSearcher;

import java.io.IOException;
import java.util.Map;

LinearFloatFunction implements a linear function over another ValueSource.
Normally Used as an argument to a FunctionQuery
/** * <code>LinearFloatFunction</code> implements a linear function over * another {@link ValueSource}. * <br> * Normally Used as an argument to a {@link org.apache.lucene.queries.function.FunctionQuery} * * */
public class LinearFloatFunction extends ValueSource { protected final ValueSource source; protected final float slope; protected final float intercept; public LinearFloatFunction(ValueSource source, float slope, float intercept) { this.source = source; this.slope = slope; this.intercept = intercept; } @Override public String description() { return slope + "*float(" + source.description() + ")+" + intercept; } @Override public FunctionValues getValues(Map context, LeafReaderContext readerContext) throws IOException { final FunctionValues vals = source.getValues(context, readerContext); return new FloatDocValues(this) { @Override public float floatVal(int doc) throws IOException { return vals.floatVal(doc) * slope + intercept; } @Override public boolean exists(int doc) throws IOException { return vals.exists(doc); } @Override public String toString(int doc) throws IOException { return slope + "*float(" + vals.toString(doc) + ")+" + intercept; } }; } @Override public void createWeight(Map context, IndexSearcher searcher) throws IOException { source.createWeight(context, searcher); } @Override public int hashCode() { int h = Float.floatToIntBits(slope); h = (h >>> 2) | (h << 30); h += Float.floatToIntBits(intercept); h ^= (h << 14) | (h >>> 19); return h + source.hashCode(); } @Override public boolean equals(Object o) { if (LinearFloatFunction.class != o.getClass()) return false; LinearFloatFunction other = (LinearFloatFunction)o; return this.slope == other.slope && this.intercept == other.intercept && this.source.equals(other.source); } }