corr.writable.VectorWritable.java Source code

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Here is the source code for corr.writable.VectorWritable.java

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/**
 * Copyright 2012 Jee Vang 
 * 
 * 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 corr.writable;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.hadoop.io.Writable;

/**
 * A vector of double values.
 * @author Jee Vang
 *
 */
public class VectorWritable implements Writable {

    private List<Double> values;

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        Iterator<Double> iter = getValues().iterator();
        while (iter.hasNext()) {
            Double d = iter.next();
            sb.append(d.toString());
            if (iter.hasNext())
                sb.append(',');
        }
        return sb.toString();
    }

    /**
     * Adds a value.
     * @param value {@link Double}.
     */
    public void add(Double value) {
        getValues().add(value);
    }

    /**
     * Gets the value at the specified index.
     * @param index Index.
     * @return {@link Double}.
     */
    public Double get(int index) {
        return getValues().get(index);
    }

    /**
     * Gets the size of this vector.
     * @return int.
     */
    public int size() {
        return getValues().size();
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        int size = in.readInt();
        values = new ArrayList<Double>(size);

        for (int i = 0; i < size; i++) {
            double value = in.readDouble();
            values.add(value);
        }
    }

    @Override
    public void write(DataOutput out) throws IOException {
        List<Double> values = getValues();

        int size = values.size();
        out.writeInt(size);

        for (int i = 0; i < size; i++) {
            out.writeDouble(values.get(i));
        }
    }

    /**
     * Gets a {@link List} of {@link Double}.
     * @return {@link List} of {@link Double}.
     */
    private List<Double> getValues() {
        if (null == values)
            values = new ArrayList<Double>();
        return values;
    }

}