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;
24
25 import org.hipparchus.CalculusFieldElement;
26 import org.hipparchus.util.MathArrays;
27
28 /** Container for time, main and secondary state vectors as well as their derivatives.
29
30 * @see FieldOrdinaryDifferentialEquation
31 * @see FieldSecondaryODE
32 * @see FieldODEIntegrator
33 * @param <T> the type of the field elements
34 */
35
36 public class FieldODEStateAndDerivative<T extends CalculusFieldElement<T>> extends FieldODEState<T> {
37
38 /** Derivative of the primary state at time. */
39 private final T[] primaryDerivative;
40
41 /** Derivative of the secondary state at time. */
42 private final T[][] secondaryDerivative;
43
44 /** Simple constructor.
45 * <p>Calling this constructor is equivalent to call {@link
46 * #FieldODEStateAndDerivative(CalculusFieldElement, CalculusFieldElement[], CalculusFieldElement[],
47 * CalculusFieldElement[][], CalculusFieldElement[][]) FieldODEStateAndDerivative(time, state,
48 * derivative, null, null)}.</p>
49 * @param time time
50 * @param primaryState primary state at time
51 * @param primaryDerivative derivative of the primary state at time
52 */
53 public FieldODEStateAndDerivative(T time, T[] primaryState, T[] primaryDerivative) {
54 this(time, primaryState, primaryDerivative, null, null);
55 }
56
57 /** Simple constructor.
58 * @param time time
59 * @param primaryState primary state at time
60 * @param primaryDerivative derivative of the primary state at time
61 * @param secondaryState state at time (may be null)
62 * @param secondaryDerivative derivative of the state at time (may be null)
63 */
64 public FieldODEStateAndDerivative(T time, T[] primaryState, T[] primaryDerivative,
65 T[][] secondaryState, T[][] secondaryDerivative) {
66 super(time, primaryState, secondaryState);
67 this.primaryDerivative = primaryDerivative.clone();
68 this.secondaryDerivative = copy(secondaryDerivative);
69 }
70
71 /** Get derivative of the primary state at time.
72 * @return derivative of the primary state at time
73 * @see #getSecondaryDerivative(int)
74 * @see #getCompleteDerivative()
75 */
76 public T[] getPrimaryDerivative() {
77 return primaryDerivative.clone();
78 }
79
80 /** Get derivative of the secondary state at time.
81 * @param index index of the secondary set as returned
82 * by {@link FieldExpandableODE#addSecondaryEquations(FieldSecondaryODE)}
83 * (beware index 0 corresponds to primary state, secondary states start at 1)
84 * @return derivative of the secondary state at time
85 * @see #getPrimaryDerivative()
86 * @see #getCompleteDerivative()
87 */
88 public T[] getSecondaryDerivative(final int index) {
89 return index == 0 ? primaryDerivative.clone() : secondaryDerivative[index - 1].clone();
90 }
91
92 /** Get complete derivative at time.
93 * @return complete derivative at time, starting with
94 * {@link #getPrimaryDerivative() primary derivative}, followed
95 * by all {@link #getSecondaryDerivative(int) secondary derivatives} in
96 * increasing index order
97 * @see #getPrimaryDerivative()
98 * @see #getSecondaryDerivative(int)
99 */
100 public T[] getCompleteDerivative() {
101 final T[] completeDerivative = MathArrays.buildArray(getTime().getField(), getCompleteStateDimension());
102 System.arraycopy(primaryDerivative, 0, completeDerivative, 0, primaryDerivative.length);
103 int offset = primaryDerivative.length;
104 if (secondaryDerivative != null) {
105 for (int index = 0; index < secondaryDerivative.length; ++index) {
106 System.arraycopy(secondaryDerivative[index], 0,
107 completeDerivative, offset,
108 secondaryDerivative[index].length);
109 offset += secondaryDerivative[index].length;
110 }
111 }
112 return completeDerivative;
113 }
114
115 }