home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (BaseDataFetcher.java)

This example Java source code file (BaseDataFetcher.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.

Learn more about this Java project at its project page.

Java - Java tags/keywords

basedatafetcher, dataset, datasetfetcher, indarray, logger, override, string, util, warning

The BaseDataFetcher.java Java example source code

/*
 *
 *  * Copyright 2015 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.datasets.fetchers;

import java.util.List;

import org.deeplearning4j.datasets.iterator.DataSetFetcher;

import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.dataset.DataSet;
import org.nd4j.linalg.factory.Nd4j;
import org.nd4j.linalg.util.FeatureUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A base class for assisting with creation of matrices
 * with the data applyTransformToDestination fetcher
 * @author Adam Gibson
 *
 */
public abstract class BaseDataFetcher implements DataSetFetcher {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = -859588773699432365L;
	protected int cursor = 0;
	protected int numOutcomes = -1;
	protected int inputColumns = -1;
	protected DataSet curr;
	protected int totalExamples;
	protected static final Logger log = LoggerFactory.getLogger(BaseDataFetcher.class);
	
	/**
	 * Creates a feature vector
	 * @param numRows the number of examples
 	 * @return a feature vector
	 */
	protected INDArray createInputMatrix(int numRows) {
		return Nd4j.create(numRows, inputColumns);
	}
	
	/**
	 * Creates an output label matrix
	 * @param outcomeLabel the outcome label to use
	 * @return a binary vector where 1 is transform to the
	 * index specified by outcomeLabel
	 */
	protected INDArray createOutputVector(int outcomeLabel) {
		return FeatureUtil.toOutcomeVector(outcomeLabel, numOutcomes);
	}
	
	protected INDArray createOutputMatrix(int numRows) {
		return Nd4j.create(numRows,numOutcomes);
	}
	
	/**
	 * Initializes this data transform fetcher from the passed in datasets
	 * @param examples the examples to use
	 */
	protected void initializeCurrFromList(List<DataSet> examples) {
		
		if(examples.isEmpty())
			log.warn("Warning: empty dataset from the fetcher");
		curr = null;
		INDArray inputs = createInputMatrix(examples.size());
		INDArray labels = createOutputMatrix(examples.size());
		for(int i = 0; i < examples.size(); i++) {
			INDArray data = examples.get(i).getFeatureMatrix();
			INDArray label = examples.get(i).getLabels();
			inputs.putRow(i, data);
			labels.putRow(i,label);
		}
		curr = new DataSet(inputs,labels);
        examples.clear();

	}

	/**
	 * Sets a list of label names to the curr dataset
	 */
	public void setLabelNames(List<String > names) {
		curr.setLabelNames(names);
	}

	public String getLabelName(int i) {
		return curr.getLabelNames().get(i);
	}
	@Override
	public boolean hasMore() {
		return cursor < totalExamples;
	}

	@Override
	public DataSet next() {
		return curr;
	}

	@Override
	public int totalOutcomes() {
		return numOutcomes;
	}

	@Override
	public int inputColumns() {
		return inputColumns;
	}

	@Override
	public int totalExamples() {
		return totalExamples;
	}

	@Override
	public void reset() {
		cursor = 0;
	}

	@Override
	public int cursor() {
		return cursor;
	}
	
	

	
}

Other Java examples (source code examples)

Here is a short list of links related to this Java BaseDataFetcher.java source code file:



my book on functional programming

 

new blog posts

 

Copyright 1998-2019 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.