org.apache.mahout.math.VectorTest.java Source code

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Here is the source code for org.apache.mahout.math.VectorTest.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 org.apache.mahout.math;

import junit.framework.TestCase;
import org.apache.hadoop.io.Writable;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.IOException;

public class VectorTest extends TestCase {

    public void testSequentialAccessSparseVectorWritable() throws Exception {
        Vector v = new SequentialAccessSparseVector(5);
        v.set(1, 3.0);
        v.set(3, 5.0);
        doTestVectorWritableEquals(v);
    }

    public void testRandomAccessSparseVectorWritable() throws Exception {
        Vector v = new RandomAccessSparseVector(5);
        v.set(1, 3.0);
        v.set(3, 5.0);
        doTestVectorWritableEquals(v);
    }

    public void testDenseVectorWritable() throws Exception {
        Vector v = new DenseVector(5);
        v.set(1, 3.0);
        v.set(3, 5.0);
        doTestVectorWritableEquals(v);
    }

    private static void doTestVectorWritableEquals(Vector v) throws IOException {
        Writable vectorWritable = new VectorWritable(v);
        VectorWritable vectorWritable2 = new VectorWritable();
        writeAndRead(vectorWritable, vectorWritable2);
        Vector v2 = vectorWritable2.get();
        assertEquals(v, v2);
    }

    private static void writeAndRead(Writable toWrite, Writable toRead) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutput dos = new DataOutputStream(baos);
        toWrite.write(dos);

        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
        DataInput dis = new DataInputStream(bais);
        toRead.readFields(dis);
    }

}