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Java example source code file (EvaluateFlatMapFunction.java)

This example Java source code file (EvaluateFlatMapFunction.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, dataset, evaluated, evaluateflatmapfunction, evaluation, exception, illegalstateexception, indarray, iterable, logger, multilayernetwork, network, override, util

The EvaluateFlatMapFunction.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.multilayer.evaluation;

import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.broadcast.Broadcast;
import org.deeplearning4j.eval.Evaluation;
import org.deeplearning4j.nn.conf.MultiLayerConfiguration;
import org.deeplearning4j.nn.multilayer.MultiLayerNetwork;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.dataset.DataSet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

/**Function to evaluate data (classification), in a distributed manner
 * Flat map function used to batch examples for computational efficiency + reduce number of Evaluation objects returned
 * for network efficiency.
 * @author Alex Black
public class EvaluateFlatMapFunction implements FlatMapFunction<Iterator {

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

    protected Broadcast<String> json;
    protected Broadcast<INDArray> params;
    protected Broadcast<List labels;
    protected int evalBatchSize;

     * @param json Network configuration (json format)
     * @param params Network parameters
     * @param evalBatchSize Max examples per evaluation. Do multiple separate forward passes if data exceeds
     *                              this. Used to avoid doing too many at once (and hence memory issues)
     * @param labels list of string labels
    public EvaluateFlatMapFunction(Broadcast<String> json, Broadcast params, int evalBatchSize,
                                   Broadcast<List labels){
        this.json = json;
        this.params = params;
        this.evalBatchSize = evalBatchSize;
        this.labels = labels;

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

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

        Evaluation evaluation;
        if(labels != null) evaluation = new Evaluation(labels.getValue());
        else evaluation = new Evaluation();

        List<DataSet> collect = new ArrayList<>();
        int totalCount = 0;
        while (dataSetIterator.hasNext()) {
            int nExamples = 0;
            while (dataSetIterator.hasNext() && nExamples < evalBatchSize) {
                DataSet next = dataSetIterator.next();
                nExamples += next.numExamples();
            totalCount += nExamples;

            DataSet data = DataSet.merge(collect, false);

            INDArray out;
            if(data.hasMaskArrays()) {
                out = network.output(data.getFeatureMatrix(), false, data.getFeaturesMaskArray(), data.getLabelsMaskArray());
            } else {
                out = network.output(data.getFeatureMatrix(), false);

            if(data.getLabels().rank() == 3){
                if(data.getLabelsMaskArray() == null){
                } else {
            } else {

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

        return Collections.singletonList(evaluation);

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