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.
29
30 * @see FieldOrdinaryDifferentialEquation
31 * @see FieldSecondaryODE
32 * @see FieldODEIntegrator
33 * @see FieldODEStateAndDerivative
34 * @param <T> the type of the field elements
35 */
36
37 public class FieldODEState<T extends CalculusFieldElement<T>> {
38
39 /** Time. */
40 private final T time;
41
42 /** Primary state at time. */
43 private final T[] primaryState;
44
45 /** Secondary state at time. */
46 private final T[][] secondaryState;
47
48 /** Complete dimension. */
49 private final int completeDimension;
50
51 /** Simple constructor.
52 * <p>Calling this constructor is equivalent to call {@link
53 * #FieldODEState(CalculusFieldElement, CalculusFieldElement[], CalculusFieldElement[][])
54 * FieldODEState(time, state, null)}.</p>
55 * @param time time
56 * @param primaryState primary state at time
57 */
58 public FieldODEState(T time, T[] primaryState) {
59 this(time, primaryState, null);
60 }
61
62 /** Simple constructor.
63 * @param time time
64 * @param primaryState primary state at time
65 * @param secondaryState secondary state at time (may be null)
66 */
67 public FieldODEState(T time, T[] primaryState, T[][] secondaryState) {
68
69 this.time = time;
70 this.primaryState = primaryState.clone();
71 this.secondaryState = copy(secondaryState);
72
73 // compute once and for all the complete dimension
74 int dimension = primaryState.length;
75 if (secondaryState != null) {
76 for (final T[] secondary : secondaryState) {
77 dimension += secondary.length;
78 }
79 }
80 this.completeDimension = dimension;
81
82 }
83
84 /** Copy a two-dimensions array.
85 * @param original original array (may be null)
86 * @return copied array or null if original array was null
87 */
88 protected T[][] copy(final T[][] original) {
89
90 // special handling of null arrays
91 if (original == null) {
92 return null; // NOPMD
93 }
94
95 // allocate the array
96 final T[][] copied = MathArrays.buildArray(time.getField(), original.length, -1);
97
98 // copy content
99 for (int i = 0; i < original.length; ++i) {
100 copied[i] = original[i].clone();
101 }
102
103 return copied;
104
105 }
106
107 /** Get time.
108 * @return time
109 */
110 public T getTime() {
111 return time;
112 }
113
114 /** Get primary state dimension.
115 * @return primary state dimension
116 * @see #getSecondaryStateDimension(int)
117 * @see #getCompleteStateDimension()
118 */
119 public int getPrimaryStateDimension() {
120 return primaryState.length;
121 }
122
123 /** Get primary state at time.
124 * @return primary state at time
125 * @see #getSecondaryState(int)
126 * @see #getCompleteState()
127 */
128 public T[] getPrimaryState() {
129 return primaryState.clone();
130 }
131
132 /** Get the number of secondary states.
133 * @return number of secondary states.
134 */
135 public int getNumberOfSecondaryStates() {
136 return secondaryState == null ? 0 : secondaryState.length;
137 }
138
139 /** Get secondary state dimension.
140 * @param index index of the secondary set as returned
141 * by {@link FieldExpandableODE#addSecondaryEquations(FieldSecondaryODE)}
142 * (beware index 0 corresponds to primary state, secondary states start at 1)
143 * @return secondary state dimension
144 */
145 public int getSecondaryStateDimension(final int index) {
146 return index == 0 ? primaryState.length : secondaryState[index - 1].length;
147 }
148
149 /** Get secondary state at time.
150 * @param index index of the secondary set as returned
151 * by {@link FieldExpandableODE#addSecondaryEquations(FieldSecondaryODE)}
152 * (beware index 0 corresponds to primary state, secondary states start at 1)
153 * @return secondary state at time
154 */
155 public T[] getSecondaryState(final int index) {
156 return index == 0 ? primaryState.clone() : secondaryState[index - 1].clone();
157 }
158
159 /** Return the dimension of the complete set of equations.
160 * <p>
161 * The complete set of equations correspond to the primary set plus all secondary sets.
162 * </p>
163 * @return dimension of the complete set of equations
164 */
165 public int getCompleteStateDimension() {
166 return completeDimension;
167 }
168
169 /** Get complete state at time.
170 * @return complete state at time, starting with
171 * {@link #getPrimaryState() primary state}, followed
172 * by all {@link #getSecondaryState(int) secondary states} in
173 * increasing index order
174 * @see #getPrimaryState()
175 * @see #getSecondaryState(int)
176 */
177 public T[] getCompleteState() {
178 final T[] completeState = MathArrays.buildArray(time.getField(), getCompleteStateDimension());
179 System.arraycopy(primaryState, 0, completeState, 0, primaryState.length);
180 int offset = primaryState.length;
181 if (secondaryState != null) {
182 for (int index = 0; index < secondaryState.length; ++index) {
183 System.arraycopy(secondaryState[index], 0,
184 completeState, offset,
185 secondaryState[index].length);
186 offset += secondaryState[index].length;
187 }
188 }
189 return completeState;
190 }
191
192 }