DoubleList.java Source code

Introduction

Here is the source code for DoubleList.java

Source

/* Copyright (C) 2002 Univ. of Massachusetts Amherst, Computer Science Dept.
   This file is part of "MALLET" (MAchine Learning for LanguagE Toolkit).
   http://www.cs.umass.edu/~mccallum/mallet
   This software is provided under the terms of the Common Public License,
   version 1.0, as published by http://www.opensource.org.  For further
   information, see the file `LICENSE' included with this distribution. */

/**
A dynamically growable list of doubles.
    
   @author Andrew McCallum <a href="mailto:mccallum@cs.umass.edu">mccallum@cs.umass.edu</a>
 */

//package cc.mallet.util;

import java.util.Arrays;
import java.io.*;

public class DoubleList implements Serializable {
    double[] data;
    int size;

    public DoubleList() {
        this(2);
    }

    // Creates a list of zero size
    public DoubleList(int capacity) {
        if (capacity < 2)
            capacity = 2;
        this.data = new double[capacity];
        this.size = 0;
    }

    public DoubleList(int size, double fillValue) {
        int capacity = size;
        if (capacity < 2)
            capacity = 2;
        this.data = new double[capacity];
        Arrays.fill(this.data, fillValue);
        this.size = size;
    }

    public DoubleList(double[] initialValues, int size) {
        this.data = new double[initialValues.length];
        System.arraycopy(initialValues, 0, this.data, 0, initialValues.length);
        this.size = size;
    }

    public DoubleList(double[] initialValues) {
        this(initialValues, initialValues.length);
    }

    public DoubleList cloneDoubleList() {
        return new DoubleList(data, size);
    }

    public Object clone() {
        return cloneDoubleList();
    }

    private void growIfNecessary(int index) {
        int newDataLength = data.length;
        while (index >= newDataLength) {
            if (newDataLength < 100)
                newDataLength *= 2;
            else
                newDataLength = (newDataLength * 3) / 2;
        }
        if (newDataLength != data.length) {
            double[] newData = new double[newDataLength];
            System.arraycopy(data, 0, newData, 0, data.length);
            data = newData;
        }
    }

    public void add(double value) {
        growIfNecessary(size);
        data[size++] = value;
    }

    public double get(int index) {
        if (index >= size)
            throw new IllegalArgumentException("Index " + index + " out of bounds; size=" + size);
        return data[index];
    }

    public void set(int index, double value) {
        growIfNecessary(index);
        data[index] = value;
        if (index >= size)
            size = index + 1;
    }

    // Serialization 

    private static final long serialVersionUID = 1;
    private static final int CURRENT_SERIAL_VERSION = 0;

    private void writeObject(ObjectOutputStream out) throws IOException {
        out.writeInt(CURRENT_SERIAL_VERSION);
        int size = data.length;
        out.writeInt(size);
        for (int i = 1; i < size; i++) {
            out.writeDouble(data[i]);
        }
        out.writeInt(this.size);
    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        int version = in.readInt();
        int len = in.readInt();
        data = new double[len];
        for (int i = 1; i < len; i++) {
            data[i] = in.readDouble();
        }
        size = in.readInt();
    }

}