/*
* 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 java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Collection;
import java.util.List;
import java.util.Random;
import com.google.common.collect.Lists;
import org.apache.mahout.common.RandomUtils;
import org.apache.mahout.math.function.DoubleDoubleFunction;
import org.apache.mahout.math.function.Functions;
import org.apache.mahout.math.jet.math.Constants;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import static org.junit.Assert.assertEquals;
@RunWith(Parameterized.class)
public class FunctionTest {
private static final int NUM_POINTS = 100;
private final Random random = RandomUtils.getRandom();
private DoubleDoubleFunction function;
private String functionName;
@Parameterized.Parameters
public static Collection<Object[]> generateData() {
List<Object[]> data = Lists.newArrayList();
for (Field field : Functions.class.getDeclaredFields()) {
if (field.getType().isAssignableFrom(DoubleDoubleFunction.class)
&& Modifier.isStatic(field.getModifiers())
&& !field.getName().equals("SECOND_LEFT_ZERO")) {
try {
data.add(new Object[] {field.get(null), field.getName()});
} catch (IllegalAccessException e) {
System.out.printf("Couldn't access Functions field %s\n", field.getName());
}
}
}
return data;
}
public FunctionTest(DoubleDoubleFunction function, String functionName) {
this.function = function;
this.functionName = functionName;
}
@Test
public void testIsLikeRightPlus() {
if (!function.isLikeRightPlus()) {
return;
}
for (int i = 0; i < NUM_POINTS; ++i) {
double x = random.nextDouble();
assertEquals(functionName, x, function.apply(x, 0), 0);
}
}
@Test
public void testIsLikeLeftMult() {
if (!function.isLikeLeftMult()) {
return;
}
for (int i = 0; i < NUM_POINTS; ++i) {
double y = random.nextDouble();
assertEquals(functionName, 0, function.apply(0, y), 0);
}
}
@Test
public void testIsLikeRightMult() {
if (!function.isLikeRightMult()) {
return;
}
for (int i = 0; i < NUM_POINTS; ++i) {
double x = random.nextDouble();
assertEquals(functionName, 0, function.apply(x, 0), 0);
}
}
@Test
public void testIsCommutative() {
if (!function.isCommutative()) {
return;
}
for (int i = 0; i < NUM_POINTS; ++i) {
double x = random.nextDouble();
double y = random.nextDouble();
assertEquals(functionName, function.apply(x, y), function.apply(y, x), Constants.EPSILON);
}
}
@Test
public void testIsAssociative() {
if (!function.isAssociative()) {
return;
}
for (int i = 0; i < NUM_POINTS; ++i) {
double x = random.nextDouble();
double y = random.nextDouble();
double z = random.nextDouble();
assertEquals(functionName, function.apply(x, function.apply(y, z)), function.apply(function.apply(x, y), z),
Constants.EPSILON);
}
}
@Test
public void testIsDensifying() {
if (!function.isDensifying()) {
assertEquals(functionName, 0, function.apply(0, 0), 0);
}
}
}