/*
* 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.commons.math3.analysis.integration.gauss;
import org.apache.commons.math3.analysis.UnivariateFunction;
import org.apache.commons.math3.analysis.function.Constant;
import org.apache.commons.math3.util.Pair;
import org.junit.Test;
import org.junit.Assert;
/**
* Test for {@link GaussIntegrator} class.
*
*/
public class GaussIntegratorTest {
@Test
public void testGetWeights() {
final double[] points = { 0, 1.2, 3.4 };
final double[] weights = { 9.8, 7.6, 5.4 };
final GaussIntegrator integrator
= new GaussIntegrator(new Pair<double[], double[]>(points, weights));
Assert.assertEquals(weights.length, integrator.getNumberOfPoints());
for (int i = 0; i < integrator.getNumberOfPoints(); i++) {
Assert.assertEquals(weights[i], integrator.getWeight(i), 0d);
}
}
@Test
public void testGetPoints() {
final double[] points = { 0, 1.2, 3.4 };
final double[] weights = { 9.8, 7.6, 5.4 };
final GaussIntegrator integrator
= new GaussIntegrator(new Pair<double[], double[]>(points, weights));
Assert.assertEquals(points.length, integrator.getNumberOfPoints());
for (int i = 0; i < integrator.getNumberOfPoints(); i++) {
Assert.assertEquals(points[i], integrator.getPoint(i), 0d);
}
}
@Test
public void testIntegrate() {
final double[] points = { 0, 1, 2, 3, 4, 5 };
final double[] weights = { 1, 1, 1, 1, 1, 1 };
final GaussIntegrator integrator
= new GaussIntegrator(new Pair<double[], double[]>(points, weights));
final double val = 123.456;
final UnivariateFunction c = new Constant(val);
final double s = integrator.integrate(c);
Assert.assertEquals(points.length * val, s, 0d);
}
}