org.qcri.pca.MahoutCompatibilityTest.java Source code

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Here is the source code for org.qcri.pca.MahoutCompatibilityTest.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.qcri.pca;

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

import org.apache.hadoop.io.Writable;
import org.apache.mahout.math.Matrix;
import org.apache.mahout.math.NamedVector;
import org.apache.mahout.math.SequentialAccessSparseVector;
import org.apache.mahout.math.SparseMatrix;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorView;
import org.apache.mahout.math.VectorWritable;
import org.junit.Test;

import com.google.common.io.Closeables;

public final class MahoutCompatibilityTest extends PCATestCase {

    @Test
    public void testMAHOUT_1221() {
        // create a matrix with an unassigned row 0
        Matrix matrix = new SparseMatrix(1, 1);
        Vector view = matrix.viewRow(0);
        final double value = 1.23;
        view.assign(value);
        // test whether the update in the view is reflected in the matrix
        assertEquals("Matrix valye", view.getQuick(0), matrix.getQuick(0, 0), EPSILON);
    }

    @Test
    public void testMAHOUT_1238() throws IOException {
        Vector v = new SequentialAccessSparseVector(5);
        v.set(1, 3.0);
        v.set(3, 5.0);
        Vector view = new VectorView(v, 0, v.size());
        doTestVectorWritableEquals(view);
    }

    private static void doTestVectorWritableEquals(Vector v) throws IOException {
        Writable vectorWritable = new VectorWritable(v);
        VectorWritable vectorWritable2 = new VectorWritable();
        writeAndRead(vectorWritable, vectorWritable2);
        Vector v2 = vectorWritable2.get();
        if (v instanceof NamedVector) {
            assertTrue(v2 instanceof NamedVector);
            NamedVector nv = (NamedVector) v;
            NamedVector nv2 = (NamedVector) v2;
            assertEquals(nv.getName(), nv2.getName());
            assertEquals("Victor", nv.getName());
        }
        assertEquals(v, v2);
    }

    private static void writeAndRead(Writable toWrite, Writable toRead) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(baos);
        try {
            toWrite.write(dos);
        } finally {
            Closeables.close(dos, true);
        }

        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
        DataInputStream dis = new DataInputStream(bais);
        try {
            toRead.readFields(dis);
        } finally {
            Closeables.close(dos, true);
        }
    }

}