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.ode.sampling;
24
25 import org.hipparchus.CalculusFieldElement;
26 import org.hipparchus.ode.FieldODEStateAndDerivative;
27
28 /**
29 * This interface represents a handler that should be called after
30 * each successful step.
31 *
32 * <p>The ODE integrators compute the evolution of the state vector at
33 * some grid points that depend on their own internal algorithm. Once
34 * they have found a new grid point (possibly after having computed
35 * several evaluation of the derivative at intermediate points), they
36 * provide it to objects implementing this interface. These objects
37 * typically either ignore the intermediate steps and wait for the
38 * last one, store the points in an ephemeris, or forward them to
39 * specialized processing or output methods.</p>
40 *
41 * @see org.hipparchus.ode.FieldODEIntegrator
42 * @see FieldODEStateInterpolator
43 * @param <T> the type of the field elements
44 */
45
46 public interface FieldODEStepHandler<T extends CalculusFieldElement<T>> {
47
48 /** Initialize step handler at the start of an ODE integration.
49 * <p>
50 * This method is called once at the start of the integration. It
51 * may be used by the step handler to initialize some internal data
52 * if needed.
53 * </p>
54 * <p>
55 * The default implementation does nothing.
56 * </p>
57 * @param initialState initial time, state vector and derivative
58 * @param finalTime target time for the integration
59 */
60 default void init(FieldODEStateAndDerivative<T> initialState, T finalTime) {
61 // nothing by default
62 }
63
64 /**
65 * Handle the last accepted step.
66 * @param interpolator interpolator for the last accepted step
67 */
68 void handleStep(FieldODEStateInterpolator<T> interpolator);
69
70 /**
71 * Finalize integration.
72 * @param finalState state at integration end
73 * @since 2.0
74 */
75 default void finish(FieldODEStateAndDerivative<T> finalState) {
76 // nothing by default
77 }
78
79 }