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  package org.apache.commons.math.analysis;
18  
19  import java.io.Serializable;
20  
21  import org.apache.commons.math.FunctionEvaluationException;
22  
23  /**
24   * Auxillary class for testing solvers.
25   *
26   * @version $Revision: 480442 $ $Date: 2006-11-29 00:21:22 -0700 (Wed, 29 Nov 2006) $ 
27   */
28  public class QuinticFunction implements DifferentiableUnivariateRealFunction, Serializable {
29  
30      private static final long serialVersionUID = -8866263034920607152L;
31  
32      /* Evaluate quintic.
33       * @see org.apache.commons.math.UnivariateRealFunction#value(double)
34       */
35      public double value(double x) throws FunctionEvaluationException {
36          return (x-1)*(x-0.5)*x*(x+0.5)*(x+1);
37      }
38  
39      public UnivariateRealFunction derivative() {
40          return new UnivariateRealFunction() {
41              public double value(double x) throws FunctionEvaluationException {
42                  return (5*x*x-3.75)*x*x+0.25;
43              }
44          };
45      }
46  }