Commons Math example source code file (UnivariateRealSolverUtilsTest.java)

This example Commons Math source code file (UnivariateRealSolverUtilsTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Math tags/keywords

expecting, expecting, illegalargumentexception, illegalargumentexception, mathexception, mathexception, sinfunction, testcase, univariaterealfunction, univariaterealfunction, univariaterealsolverutilstest

The Commons Math UnivariateRealSolverUtilsTest.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.solvers;

import junit.framework.TestCase;

import org.apache.commons.math.MathException;
import org.apache.commons.math.analysis.SinFunction;
import org.apache.commons.math.analysis.UnivariateRealFunction;

/**
 * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $
 */
public class UnivariateRealSolverUtilsTest extends TestCase {

    protected UnivariateRealFunction sin = new SinFunction();

    public void testSolveNull() throws MathException {
        try {
            UnivariateRealSolverUtils.solve(null, 0.0, 4.0);
            fail();
        } catch(IllegalArgumentException ex){
            // success
        }
    }

    public void testSolveBadParameters() throws MathException {
        try { // bad endpoints
            UnivariateRealSolverUtils.solve(sin,0.0, 4.0, 4.0);
        } catch (IllegalArgumentException ex) {
            // expected
        }
        try { // bad accuracy
            UnivariateRealSolverUtils.solve(sin, 0.0, 4.0, 0.0);
        } catch (IllegalArgumentException ex) {
            // expected
        }
    }

    public void testSolveSin() throws MathException {
        double x = UnivariateRealSolverUtils.solve(sin, 1.0, 4.0);
        assertEquals(Math.PI, x, 1.0e-4);
    }

    public void testSolveAccuracyNull()  throws MathException {
        try {
            double accuracy = 1.0e-6;
            UnivariateRealSolverUtils.solve(null, 0.0, 4.0, accuracy);
            fail();
        } catch(IllegalArgumentException ex){
            // success
        }
    }

    public void testSolveAccuracySin() throws MathException {
        double accuracy = 1.0e-6;
        double x = UnivariateRealSolverUtils.solve(sin, 1.0,
                4.0, accuracy);
        assertEquals(Math.PI, x, accuracy);
    }

    public void testSolveNoRoot() throws MathException {
        try {
            UnivariateRealSolverUtils.solve(sin, 1.0, 1.5);
            fail("Expecting IllegalArgumentException ");
        } catch (IllegalArgumentException ex) {
            // expected
        }
    }

    public void testBracketSin() throws MathException {
        double[] result = UnivariateRealSolverUtils.bracket(sin,
                0.0, -2.0, 2.0);
        assertTrue(sin.value(result[0]) < 0);
        assertTrue(sin.value(result[1]) > 0);
    }

    public void testBracketEndpointRoot() throws MathException {
        double[] result = UnivariateRealSolverUtils.bracket(sin, 1.5, 0, 2.0);
        assertEquals(0.0, sin.value(result[0]), 1.0e-15);
        assertTrue(sin.value(result[1]) > 0);
    }

    public void testBadParameters() throws MathException {
        try { // null function
            UnivariateRealSolverUtils.bracket(null, 1.5, 0, 2.0);
            fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }
        try { // initial not between endpoints
            UnivariateRealSolverUtils.bracket(sin, 2.5, 0, 2.0);
            fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }
        try { // endpoints not valid
            UnivariateRealSolverUtils.bracket(sin, 1.5, 2.0, 1.0);
            fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }
        try { // bad maximum iterations
            UnivariateRealSolverUtils.bracket(sin, 1.5, 0, 2.0, 0);
            fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }
    }

}