1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.math4.legacy.analysis.solvers;
19
20 import org.apache.commons.math4.legacy.analysis.UnivariateFunction;
21 import org.apache.commons.math4.legacy.exception.ConvergenceException;
22 import org.apache.commons.math4.core.jdkmath.JdkMath;
23 import org.junit.Test;
24 import org.junit.Assert;
25
26 /**
27 * Test case for {@link RegulaFalsiSolver Regula Falsi} solver.
28 *
29 */
30 public final class RegulaFalsiSolverTest extends BaseSecantSolverAbstractTest {
31 /** {@inheritDoc} */
32 @Override
33 protected UnivariateSolver getSolver() {
34 return new RegulaFalsiSolver();
35 }
36
37 /** {@inheritDoc} */
38 @Override
39 protected int[] getQuinticEvalCounts() {
40 // While the Regula Falsi method guarantees convergence, convergence
41 // may be extremely slow. The last test case does not converge within
42 // even a million iterations. As such, it was disabled.
43 return new int[] {3, 7, 8, 19, 18, 11, 67, 55, 288, 151, -1};
44 }
45
46 @Test(expected=ConvergenceException.class)
47 public void testIssue631() {
48 final UnivariateFunction f = new UnivariateFunction() {
49 /** {@inheritDoc} */
50 @Override
51 public double value(double x) {
52 return JdkMath.exp(x) - JdkMath.pow(Math.PI, 3.0);
53 }
54 };
55
56 final UnivariateSolver solver = new RegulaFalsiSolver();
57 final double root = solver.solve(3624, f, 1, 10);
58 Assert.assertEquals(3.4341896575482003, root, 1e-15);
59 }
60 }