hu.sztaki.incremental.ml.streaming.imsr.MatrixVectorPairSource.java Source code

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Here is the source code for hu.sztaki.incremental.ml.streaming.imsr.MatrixVectorPairSource.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 hu.sztaki.incremental.ml.streaming.imsr;

import java.io.File;
import java.util.Locale;
import java.util.Scanner;
import java.util.regex.Pattern;

import org.apache.commons.math.linear.Array2DRowRealMatrix;
import org.apache.commons.math.linear.RealMatrix;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.function.source.SourceFunction;
import org.apache.flink.util.Collector;

public class MatrixVectorPairSource implements SourceFunction<Tuple2<double[][], double[][]>> {

    private static final long serialVersionUID = 2725224422071102334L;

    private String path;
    private int indepDim;
    private int batchSize;

    public MatrixVectorPairSource(String path, int batchSize) {
        this.path = path;
        this.batchSize = batchSize;
    }

    private static Scanner initCsvScanner(Scanner s) {
        s.useLocale(Locale.ENGLISH);
        s.useDelimiter("(\\s+|\\s*,\\s*)");
        return s;
    }

    @Override
    public void invoke(Collector<Tuple2<double[][], double[][]>> out) throws Exception {
        File f = new File(path);
        if (!f.exists()) {
            System.err.println(path + " does not exist.");
            System.exit(1);
        }
        Scanner s = initCsvScanner(new Scanner(f));
        String firstLine = s.nextLine();
        Scanner firstLineScanner = initCsvScanner(new Scanner(firstLine));
        for (indepDim = 0; firstLineScanner.hasNext(); firstLineScanner.next(), indepDim++)
            ;
        indepDim--;
        while (s.hasNext()) {
            Array2DRowRealMatrix X = new Array2DRowRealMatrix(batchSize, indepDim);
            Array2DRowRealMatrix y = new Array2DRowRealMatrix(batchSize, 1);
            readMatricesSideBySide(s, X, y);
            out.collect(new Tuple2<double[][], double[][]>(X.getDataRef(), y.getDataRef()));
        }
        s.close();
        out.close();
    }

    private void readMatricesSideBySide(Scanner scanner, RealMatrix... matrices) {
        for (int i = 0; i < matrices[0].getRowDimension(); i++) {
            if (!scanner.hasNextLine()) {
                return; //there will be some 0 rows
            }
            String line = scanner.nextLine();
            Scanner lineScanner = initCsvScanner(new Scanner(line));
            for (RealMatrix m : matrices) {
                for (int j = 0; j < m.getColumnDimension(); j++) {
                    double d = lineScanner.nextDouble();
                    m.setEntry(i, j, d);
                }
            }
            lineScanner.close();
        }
    }

}