/**
* 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.als;
import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.MahoutTestCase;
import org.apache.mahout.math.Matrix;
import org.apache.mahout.math.RandomAccessSparseVector;
import org.apache.mahout.math.SequentialAccessSparseVector;
import org.apache.mahout.math.SparseMatrix;
import org.apache.mahout.math.Vector;
import org.junit.Test;
import java.util.Arrays;
public class AlternatingLeastSquaresSolverTest extends MahoutTestCase {
@Test
public void addLambdaTimesNuiTimesE() {
int nui = 5;
double lambda = 0.2;
Matrix matrix = new SparseMatrix(5, 5);
AlternatingLeastSquaresSolver.addLambdaTimesNuiTimesE(matrix, lambda, nui);
for (int n = 0; n < 5; n++) {
assertEquals(1.0, matrix.getQuick(n, n), EPSILON);
}
}
@Test
public void createMiIi() {
Vector f1 = new DenseVector(new double[] { 1, 2, 3 });
Vector f2 = new DenseVector(new double[] { 4, 5, 6 });
Matrix miIi = AlternatingLeastSquaresSolver.createMiIi(Arrays.asList(f1, f2), 3);
assertEquals(1.0, miIi.getQuick(0, 0), EPSILON);
assertEquals(2.0, miIi.getQuick(1, 0), EPSILON);
assertEquals(3.0, miIi.getQuick(2, 0), EPSILON);
assertEquals(4.0, miIi.getQuick(0, 1), EPSILON);
assertEquals(5.0, miIi.getQuick(1, 1), EPSILON);
assertEquals(6.0, miIi.getQuick(2, 1), EPSILON);
}
@Test
public void createRiIiMaybeTransposed() {
Vector ratings = new SequentialAccessSparseVector(3);
ratings.setQuick(1, 1.0);
ratings.setQuick(3, 3.0);
ratings.setQuick(5, 5.0);
Matrix riIiMaybeTransposed = AlternatingLeastSquaresSolver.createRiIiMaybeTransposed(ratings);
assertEquals(1, riIiMaybeTransposed.numCols(), 1);
assertEquals(3, riIiMaybeTransposed.numRows(), 3);
assertEquals(1.0, riIiMaybeTransposed.getQuick(0, 0), EPSILON);
assertEquals(3.0, riIiMaybeTransposed.getQuick(1, 0), EPSILON);
assertEquals(5.0, riIiMaybeTransposed.getQuick(2, 0), EPSILON);
}
@Test
public void createRiIiMaybeTransposedExceptionOnNonSequentialVector() {
Vector ratings = new RandomAccessSparseVector(3);
ratings.setQuick(1, 1.0);
ratings.setQuick(3, 3.0);
ratings.setQuick(5, 5.0);
try {
AlternatingLeastSquaresSolver.createRiIiMaybeTransposed(ratings);
fail();
} catch (IllegalArgumentException e) {}
}
}