| /* |
| * 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.math4.analysis.integration.gauss; |
| |
| import org.apache.commons.math4.analysis.UnivariateFunction; |
| import org.apache.commons.math4.analysis.function.Cos; |
| import org.apache.commons.math4.analysis.function.Inverse; |
| import org.apache.commons.math4.analysis.function.Log; |
| import org.junit.Test; |
| import org.junit.Assert; |
| |
| /** |
| * Test of the {@link LegendreRuleFactory}. |
| * |
| */ |
| public class LegendreTest { |
| private static final GaussIntegratorFactory factory = new GaussIntegratorFactory(); |
| |
| @Test |
| public void testCos() { |
| final UnivariateFunction cos = new Cos(); |
| |
| final GaussIntegrator integrator = factory.legendre(7, 0, Math.PI / 2); |
| final double s = integrator.integrate(cos); |
| // System.out.println("s=" + s + " e=" + 1); |
| Assert.assertEquals(1, s, Math.ulp(1d)); |
| } |
| |
| |
| @Test |
| public void testInverse() { |
| final UnivariateFunction inv = new Inverse(); |
| final UnivariateFunction log = new Log(); |
| |
| final double lo = 12.34; |
| final double hi = 456.78; |
| |
| final GaussIntegrator integrator = factory.legendre(60, lo, hi); |
| final double s = integrator.integrate(inv); |
| final double expected = log.value(hi) - log.value(lo); |
| // System.out.println("s=" + s + " e=" + expected); |
| Assert.assertEquals(expected, s, 1e-14); |
| } |
| } |