/**
* 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.utils;
import junit.framework.TestCase;
import org.apache.mahout.matrix.DenseVector;
import org.apache.mahout.matrix.Vector;
public abstract class DefaultDistanceMeasureTest extends TestCase {
public abstract DistanceMeasure distanceMeasureFactory();
public void testMeasure() {
DistanceMeasure distanceMeasure = distanceMeasureFactory();
Vector[] vectors = {
new DenseVector(new double[]{1, 1, 1, 1, 1, 1}),
new DenseVector(new double[]{2, 2, 2, 2, 2, 2}),
new DenseVector(new double[]{6, 6, 6, 6, 6, 6})
};
double[][] distanceMatrix = new double[3][3];
for (int a = 0; a < 3; a++) {
for (int b = 0; b < 3; b++) {
distanceMatrix[a][b] = distanceMeasure.distance(vectors[a], vectors[b]);
}
}
assertEquals(0.0, distanceMatrix[0][0]);
assertTrue(distanceMatrix[0][0] < distanceMatrix[0][1]);
assertTrue(distanceMatrix[0][1] < distanceMatrix[0][2]);
assertEquals(0.0, distanceMatrix[1][1]);
assertTrue(distanceMatrix[1][0] > distanceMatrix[1][1]);
assertTrue(distanceMatrix[1][2] > distanceMatrix[1][0]);
assertEquals(0.0, distanceMatrix[2][2]);
assertTrue(distanceMatrix[2][0] > distanceMatrix[2][1]);
assertTrue(distanceMatrix[2][1] > distanceMatrix[2][2]);
}
}