1 /*
2 * Licensed to the Hipparchus project 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 Hipparchus project 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 package org.hipparchus.ode;
19
20 import org.hipparchus.complex.Complex;
21
22 /** This interface represents a first order differential equations set for {@link Complex complex state}.
23 *
24 * @see OrdinaryDifferentialEquation
25 * @see ComplexODEConverter
26 * @since 1.4
27 *
28 */
29 public interface ComplexOrdinaryDifferentialEquation {
30
31 /** Get the dimension of the problem.
32 * @return dimension of the problem
33 */
34 int getDimension();
35
36 /** Initialize equations at the start of an ODE integration.
37 * <p>
38 * This method is called once at the start of the integration. It
39 * may be used by the equations to initialize some internal data
40 * if needed.
41 * </p>
42 * <p>
43 * The default implementation does nothing.
44 * </p>
45 * @param t0 value of the independent <I>time</I> variable at integration start
46 * @param y0 array containing the value of the state vector at integration start
47 * @param finalTime target time for the integration
48 */
49 default void init(double t0, Complex[] y0, double finalTime) {
50 // do nothing by default
51 }
52
53 /** Get the current time derivative of the state vector.
54 * @param t current value of the independent <I>time</I> variable
55 * @param y array containing the current value of the state vector
56 * @return time derivative of the state vector
57 */
58 Complex[] computeDerivatives(double t, Complex[] y);
59
60 }