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 * https://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 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22
23 package org.hipparchus.migration.ode.sampling;
24
25 import org.hipparchus.ode.ODEStateAndDerivative;
26 import org.hipparchus.ode.sampling.ODEFixedStepHandler;
27
28 /**
29 * This interface represents a handler that should be called after
30 * each successful fixed step.
31
32 * <p>This interface should be implemented by anyone who is interested
33 * in getting the solution of an ordinary differential equation at
34 * fixed time steps. Objects implementing this interface should be
35 * wrapped within an instance of {@link org.hipparchus.ode.sampling.StepNormalizer} that itself
36 * is used as the general {@link StepHandler} by the integrator. The
37 * {@link org.hipparchus.ode.sampling.StepNormalizer} object is called according to the integrator
38 * internal algorithms and it calls objects implementing this
39 * interface as necessary at fixed time steps.</p>
40 *
41 * @see StepHandler
42 * @see org.hipparchus.ode.sampling.StepNormalizer
43 * @deprecated as of 1.0, replaced with {@link ODEFixedStepHandler}
44 */
45 @Deprecated
46 public interface FixedStepHandler extends ODEFixedStepHandler {
47
48 /** {@inheritDoc}} */
49 @Override
50 default void init(final ODEStateAndDerivative initialState, final double finalTime) {
51 init(initialState.getTime(), initialState.getPrimaryState(), finalTime);
52 }
53
54 /** {@inheritDoc}} */
55 @Override
56 default void handleStep(final ODEStateAndDerivative state, final boolean isLast) {
57 handleStep(state.getTime(), state.getPrimaryState(), state.getPrimaryDerivative(), isLast);
58 }
59
60 /** Initialize step handler at the start of an ODE integration.
61 * <p>
62 * This method is called once at the start of the integration. It
63 * may be used by the step handler to initialize some internal data
64 * if needed.
65 * </p>
66 * @param t0 start value of the independent <i>time</i> variable
67 * @param y0 array containing the start value of the state vector
68 * @param t target time for the integration
69 */
70 void init(double t0, double[] y0, double t);
71
72 /**
73 * Handle the last accepted step
74 * @param t time of the current step
75 * @param y state vector at t. For efficiency purposes, the {@link
76 * org.hipparchus.ode.sampling.StepNormalizer} class reuses the same array on each call, so if
77 * the instance wants to keep it across all calls (for example to
78 * provide at the end of the integration a complete array of all
79 * steps), it should build a local copy store this copy.
80 * @param yDot derivatives of the state vector state vector at t.
81 * For efficiency purposes, the {@link org.hipparchus.ode.sampling.StepNormalizer} class reuses
82 * the same array on each call, so if
83 * the instance wants to keep it across all calls (for example to
84 * provide at the end of the integration a complete array of all
85 * steps), it should build a local copy store this copy.
86 * @param isLast true if the step is the last one
87 */
88 void handleStep(double t, double[] y, double[] yDot, boolean isLast);
89
90 }