com.davidbracewell.math.similarity.AbstractCorrelationSimilarity.java Source code

Introduction

Here is the source code for com.davidbracewell.math.similarity.AbstractCorrelationSimilarity.java

Source

/*
 * (c) 2005 David B. Bracewell
 *
 * 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
 *
 * 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 com.davidbracewell.math.similarity;

import com.davidbracewell.collection.Index;
import com.davidbracewell.collection.Indexes;
import com.davidbracewell.math.ContingencyTable;
import com.davidbracewell.math.linear.Vector;
import com.google.common.base.Preconditions;
import com.google.common.collect.Sets;

import java.util.Map;

/**
 * @author David B. Bracewell
 */
public abstract class AbstractCorrelationSimilarity extends SimilarityMeasure {

    private static final long serialVersionUID = -2283302761286695056L;

    @Override
    public double calculate(Map<?, ? extends Number> m1, Map<?, ? extends Number> m2) {
        Preconditions.checkNotNull(m1, "Vectors cannot be null");
        Preconditions.checkNotNull(m2, "Vectors cannot be null");
        Index index = Indexes.newIndex(Sets.union(m1.keySet(), m2.keySet()));
        double[] v1 = new double[index.size()];
        double[] v2 = new double[index.size()];
        for (int i = 0; i < index.size(); i++) {
            v1[i] = m1.containsKey(index.get(i)) ? m1.get(index.get(i)).doubleValue() : 0d;
            v2[i] = m2.containsKey(index.get(i)) ? m2.get(index.get(i)).doubleValue() : 0d;
        }
        return calculate(v1, v2);
    }

    @Override
    public double calculate(Vector v1, Vector v2) {
        Preconditions.checkNotNull(v1, "Vectors cannot be null");
        Preconditions.checkNotNull(v2, "Vectors cannot be null");
        Preconditions.checkArgument(v1.dimension() == v2.dimension(),
                "Vector dimension mismatch " + v1.dimension() + " != " + v2.dimension());
        return calculate(v1.toArray(), v2.toArray());
    }

    @Override
    public double calculate(ContingencyTable table) {
        throw new UnsupportedOperationException();
    }
}//END OF AbstractCorrelationSimilarity