View Javadoc

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.math.ode.sampling;
19  
20  import org.apache.commons.math.ode.DerivativeException;
21  
22  /**
23   * This interface represents a handler that should be called after
24   * each successful fixed step.
25  
26   * <p>This interface should be implemented by anyone who is interested
27   * in getting the solution of an ordinary differential equation at
28   * fixed time steps. Objects implementing this interface should be
29   * wrapped within an instance of {@link StepNormalizer} that itself
30   * is used as the general {@link StepHandler} by the integrator. The
31   * {@link StepNormalizer} object is called according to the integrator
32   * internal algorithms and it calls objects implementing this
33   * interface as necessary at fixed time steps.</p>
34   *
35   * @see StepHandler
36   * @see StepNormalizer
37   * @version $Revision: 785473 $ $Date: 2009-06-17 00:02:35 -0400 (Wed, 17 Jun 2009) $
38   * @since 1.2
39   */
40  
41  public interface FixedStepHandler  {
42  
43    /**
44     * Handle the last accepted step
45     * @param t time of the current step
46     * @param y state vector at t. For efficiency purposes, the {@link
47     * StepNormalizer} class reuses the same array on each call, so if
48     * the instance wants to keep it across all calls (for example to
49     * provide at the end of the integration a complete array of all
50     * steps), it should build a local copy store this copy.
51     * @param yDot derivatives of the state vector state vector at t.
52     * For efficiency purposes, the {@link StepNormalizer} class reuses
53     * the same array on each call, so if
54     * the instance wants to keep it across all calls (for example to
55     * provide at the end of the integration a complete array of all
56     * steps), it should build a local copy store this copy.
57     * @param isLast true if the step is the last one
58     * @throws DerivativeException if some error condition is encountered
59     */
60    public void handleStep(double t, double[] y, double[] yDot, boolean isLast)
61        throws DerivativeException;
62  
63  }