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Commons Math example source code file (RombergIntegratorTest.java)
The Commons Math RombergIntegratorTest.java source code/* * 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.math.analysis.integration; import org.apache.commons.math.MathException; import org.apache.commons.math.analysis.QuinticFunction; import org.apache.commons.math.analysis.SinFunction; import org.apache.commons.math.analysis.UnivariateRealFunction; import junit.framework.TestCase; /** * Testcase for Romberg integrator. * <p> * Romberg algorithm is very fast for good behavior integrand. Test runs * show that for a default relative accuracy of 1E-6, it generally takes * takes less than 5 iterations for the integral to converge. * * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $ */ public final class RombergIntegratorTest extends TestCase { /** * Test of integrator for the sine function. */ public void testSinFunction() throws MathException { UnivariateRealFunction f = new SinFunction(); UnivariateRealIntegrator integrator = new RombergIntegrator(); double min, max, expected, result, tolerance; min = 0; max = Math.PI; expected = 2; tolerance = Math.abs(expected * integrator.getRelativeAccuracy()); result = integrator.integrate(f, min, max); assertEquals(expected, result, tolerance); min = -Math.PI/3; max = 0; expected = -0.5; tolerance = Math.abs(expected * integrator.getRelativeAccuracy()); result = integrator.integrate(f, min, max); assertEquals(expected, result, tolerance); } /** * Test of integrator for the quintic function. */ public void testQuinticFunction() throws MathException { UnivariateRealFunction f = new QuinticFunction(); UnivariateRealIntegrator integrator = new RombergIntegrator(); double min, max, expected, result, tolerance; min = 0; max = 1; expected = -1.0/48; tolerance = Math.abs(expected * integrator.getRelativeAccuracy()); result = integrator.integrate(f, min, max); assertEquals(expected, result, tolerance); min = 0; max = 0.5; expected = 11.0/768; tolerance = Math.abs(expected * integrator.getRelativeAccuracy()); result = integrator.integrate(f, min, max); assertEquals(expected, result, tolerance); min = -1; max = 4; expected = 2048/3.0 - 78 + 1.0/48; tolerance = Math.abs(expected * integrator.getRelativeAccuracy()); result = integrator.integrate(f, min, max); assertEquals(expected, result, tolerance); } /** * Test of parameters for the integrator. */ public void testParameters() throws Exception { UnivariateRealFunction f = new SinFunction(); UnivariateRealIntegrator integrator = new RombergIntegrator(); try { // bad interval integrator.integrate(f, 1, -1); fail("Expecting IllegalArgumentException - bad interval"); } catch (IllegalArgumentException ex) { // expected } try { // bad iteration limits integrator.setMinimalIterationCount(5); integrator.setMaximalIterationCount(4); integrator.integrate(f, -1, 1); fail("Expecting IllegalArgumentException - bad iteration limits"); } catch (IllegalArgumentException ex) { // expected } try { // bad iteration limits integrator.setMinimalIterationCount(10); integrator.setMaximalIterationCount(50); integrator.integrate(f, -1, 1); fail("Expecting IllegalArgumentException - bad iteration limits"); } catch (IllegalArgumentException ex) { // expected } } } Other Commons Math examples (source code examples)Here is a short list of links related to this Commons Math RombergIntegratorTest.java source code file: |
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