/**
* 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.
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package org.apache.mahout.math.hadoop.solver;
import java.io.File;
import java.util.Random;
import org.apache.mahout.common.MahoutTestCase;
import org.apache.mahout.common.RandomUtils;
import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.hadoop.DistributedRowMatrix;
import org.apache.mahout.math.hadoop.TestDistributedRowMatrix;
import org.junit.Test;
public final class TestDistributedConjugateGradientSolver extends MahoutTestCase {
private static Vector randomVector(int size, double entryMean) {
DenseVector v = new DenseVector(size);
Random r = RandomUtils.getRandom();
for (int i = 0; i < size; ++i) {
v.setQuick(i, r.nextGaussian() * entryMean);
}
return v;
}
@Test
public void testSolver() throws Exception {
File testData = getTestTempDir("testdata");
DistributedRowMatrix matrix = new TestDistributedRowMatrix().randomDistributedMatrix(
10, 10, 10, 10, 10.0, true, testData.getAbsolutePath());
matrix.setConf(getConfiguration());
Vector vector = randomVector(matrix.numCols(), 10.0);
DistributedConjugateGradientSolver solver = new DistributedConjugateGradientSolver();
Vector x = solver.solve(matrix, vector);
Vector solvedVector = matrix.times(x);
double distance = Math.sqrt(vector.getDistanceSquared(solvedVector));
assertEquals(0.0, distance, EPSILON);
}
}