org.apache.solr.client.solrj.io.eval.UnitEvaluator.java Source code

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Here is the source code for org.apache.solr.client.solrj.io.eval.UnitEvaluator.java

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/*
 * 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 org.apache.solr.client.solrj.io.eval;

import java.io.IOException;

import java.util.Locale;

import org.apache.commons.math3.linear.RealVector;
import org.apache.commons.math3.linear.ArrayRealVector;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
import java.util.List;
import java.util.ArrayList;

public class UnitEvaluator extends RecursiveObjectEvaluator implements OneValueWorker {
    protected static final long serialVersionUID = 1L;

    public UnitEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
        super(expression, factory);

        if (1 != containedEvaluators.size()) {
            throw new IOException(
                    String.format(Locale.ROOT, "Invalid expression %s - expecting exactly 1 value but found %d",
                            expression, containedEvaluators.size()));
        }
    }

    @Override
    public Object doWork(Object value) throws IOException {
        if (null == value) {
            return null;
        } else if (value instanceof Matrix) {
            Matrix matrix = (Matrix) value;
            double[][] data = matrix.getData();
            double[][] unitData = new double[data.length][];
            for (int i = 0; i < data.length; i++) {
                double[] row = data[i];
                ArrayRealVector vector = new ArrayRealVector(row);
                double[] unitRow = vector.unitVector().toArray();
                unitData[i] = unitRow;
            }

            return new Matrix(unitData);
        } else if (value instanceof List) {
            List<Number> values = (List<Number>) value;
            double[] doubles = new double[values.size()];
            for (int i = 0; i < doubles.length; i++) {
                doubles[i] = values.get(i).doubleValue();
            }

            ArrayRealVector vector = new ArrayRealVector(doubles);
            RealVector unitVector = vector.unitVector();
            List<Number> unitList = new ArrayList(doubles.length);
            double[] unitArray = unitVector.toArray();
            for (double d : unitArray) {
                unitList.add(d);
            }

            return unitList;
        } else {
            throw new IOException("The unit function expects either a numeric array or matrix as a parameter");
        }
    }
}