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Java example source code file (ScoreExamplesWithKeyFunction.java)

This example Java source code file (ScoreExamplesWithKeyFunction.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

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Java - Java tags/keywords

arraylist, broadcast, cannot, computationgraph, illegalstateexception, indarray, list, logger, multidataset, network, override, scored, scoreexampleswithkeyfunction, tuple2, util

The ScoreExamplesWithKeyFunction.java Java example source code

 *  * Copyright 2016 Skymind,Inc.
 *  *
 *  *    Licensed 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.deeplearning4j.spark.impl.graph.scoring;

import org.apache.spark.api.java.function.PairFlatMapFunction;
import org.apache.spark.broadcast.Broadcast;
import org.deeplearning4j.nn.conf.ComputationGraphConfiguration;
import org.deeplearning4j.nn.graph.ComputationGraph;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.dataset.api.MultiDataSet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import scala.Tuple2;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

/**Function to score examples individually, where each example is associated with a particular key<br>
 * Note that scoring is batched for computational efficiency.<br>
 * This is the Spark implementation of the {@link ComputationGraph#scoreExamples(MultiDataSet, boolean)} method<br>
 * <b>Note: The MultiDataSet objects passed in must have exactly one example in them (otherwise: can't have a 1:1 association
 * between keys and data sets to score)
 * @author Alex Black
 * @param <K> Type of key, associated with each example. Used to keep track of which score belongs to which example
 * @see ScoreExamplesFunction
public class ScoreExamplesWithKeyFunction<K> implements PairFlatMapFunction>,K,Double> {

    protected static Logger log = LoggerFactory.getLogger(ScoreExamplesWithKeyFunction.class);

    private final Broadcast<INDArray> params;
    private final Broadcast<String> jsonConfig;
    private final boolean addRegularization;
    private final int batchSize;

     * @param params ComputationGraph parameters
     * @param jsonConfig ComputationGraphConfiguration, as json
     * @param addRegularizationTerms if true: add regularization terms (l1/l2) if applicable; false: don't add regularization terms
     * @param batchSize Batch size to use when scoring examples
    public ScoreExamplesWithKeyFunction(Broadcast<INDArray> params, Broadcast jsonConfig, boolean addRegularizationTerms,
                                        int batchSize){
        this.params = params;
        this.jsonConfig = jsonConfig;
        this.addRegularization = addRegularizationTerms;
        this.batchSize = batchSize;

    public Iterable<Tuple2 call(Iterator> iterator) throws Exception {
        if (!iterator.hasNext()) {
            return Collections.emptyList();

        ComputationGraph network = new ComputationGraph(ComputationGraphConfiguration.fromJson(jsonConfig.getValue()));
        INDArray val = params.value();
        if (val.length() != network.numParams(false))
            throw new IllegalStateException("Network did not have same number of parameters as the broadcast set parameters");

        List<Tuple2 ret = new ArrayList<>();

        List<MultiDataSet> collect = new ArrayList<>(batchSize);
        List<K> collectKey = new ArrayList<>(batchSize);
        int totalCount = 0;
        while (iterator.hasNext()) {
            int nExamples = 0;
            while (iterator.hasNext() && nExamples < batchSize) {
                Tuple2<K,MultiDataSet> t2 = iterator.next();
                MultiDataSet ds = t2._2();
                int n = ds.getFeatures(0).size(0);
                if(n != 1) throw new IllegalStateException("Cannot score examples with one key per data set if "
                    + "data set contains more than 1 example (numExamples: " + n + ")");
                nExamples += n;
            totalCount += nExamples;

            MultiDataSet data = org.nd4j.linalg.dataset.MultiDataSet.merge(collect);

            INDArray scores = network.scoreExamples(data,addRegularization);
            double[] doubleScores = scores.data().asDouble();

            for(int i=0; i<doubleScores.length; i++ ){
                ret.add(new Tuple2<>(collectKey.get(i),doubleScores[i]));

        if (log.isDebugEnabled()) {
            log.debug("Scored {} examples ", totalCount);

        return ret;

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