1 /* Copyright 2002-2026 CS GROUP
2 * Licensed to CS GROUP (CS) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * CS 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 * http://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 package org.orekit.propagation;
18
19 import org.hipparchus.linear.MatrixUtils;
20 import org.hipparchus.linear.RealMatrix;
21 import org.orekit.orbits.OrbitParamsType;
22 import org.orekit.orbits.PositionAngleType;
23 import org.orekit.utils.DoubleArrayDictionary;
24
25 /** Base harvester between two-dimensional Jacobian matrices and one-dimensional {@link
26 * SpacecraftState#getAdditionalState(String) additional state arrays}.
27 * @author Luc Maisonobe
28 * @since 11.1
29 */
30 public abstract class AbstractMatricesHarvester implements MatricesHarvester {
31
32 /** Default state dimension, equivalent to position and velocity vectors. */
33 public static final int DEFAULT_STATE_DIMENSION = 6;
34
35 /** State Transition Matrix state name. */
36 private String stmName;
37
38 /** Initial State Transition Matrix. */
39 private RealMatrix initialStm;
40
41 /** Initial columns of the Jacobians matrix with respect to parameters. */
42 private DoubleArrayDictionary initialJacobianColumns;
43
44 /** Empty constructor.
45 * <p>
46 * This constructor is not strictly necessary, but it prevents spurious
47 * javadoc warnings with JDK 18 and later.
48 * </p>
49 * @since 14.0
50 */
51 public AbstractMatricesHarvester() {
52 // nothing to do
53 }
54
55 /** Set the initial State Transition Matrix.
56 * <p>
57 * The arguments for initial matrices <em>must</em> be compatible with the
58 * {@link OrbitParamsType orbit type} and
59 * {@link PositionAngleType position angle} that will be used by propagator,
60 * which may be different from input and output
61 * </p>
62 * @param name State Transition Matrix state name
63 * @param stm initial State Transition Matrix āY/āIā
64 * if null (which is the most frequent case), input and output
65 * orbit types are assumed to be identical and the matrix is
66 * assumed to be the 6x6 identity
67 */
68 protected void setInitialStm(final String name, final RealMatrix stm) {
69 this.stmName = name;
70 this.initialStm = stm == null ?
71 MatrixUtils.createRealIdentityMatrix(DEFAULT_STATE_DIMENSION) :
72 stm;
73 }
74
75 /** Set the initial columns of the Jacobians matrix with respect to parameters.
76 * <p>
77 * The arguments for initial matrices <em>must</em> be compatible with the
78 * {@link OrbitParamsType orbit type} and
79 * {@link PositionAngleType position angle} that will be used by propagator
80 * </p>
81 * @param initialJacobianColumns initial columns of the Jacobians matrix with respect to parameters,
82 * if null or if some selected parameters are missing from the dictionary, the corresponding
83 * initial column is assumed to be 0
84 */
85 protected void setInitialJacobianColumns(final DoubleArrayDictionary initialJacobianColumns) {
86 this.initialJacobianColumns = initialJacobianColumns == null ?
87 new DoubleArrayDictionary() :
88 initialJacobianColumns;
89 }
90
91 /**
92 * Getter for the state dimension.
93 * @return state dimension
94 * @since 13.1
95 */
96 public int getStateDimension() {
97 return initialStm.getColumnDimension();
98 }
99
100 /** Get the State Transition Matrix state name.
101 * @return State Transition Matrix state name
102 */
103 public String getStmName() {
104 return stmName;
105 }
106
107 /** Get the initial State Transition Matrix.
108 * @return initial State Transition Matrix
109 */
110 public RealMatrix getInitialStateTransitionMatrix() {
111 return initialStm;
112 }
113
114 /** Get the initial column of Jacobian matrix with respect to named parameter.
115 * @param columnName name of the column
116 * @return initial column of the Jacobian matrix
117 */
118 public double[] getInitialJacobianColumn(final String columnName) {
119 final DoubleArrayDictionary.Entry entry = initialJacobianColumns.getEntry(columnName);
120 return entry == null ? new double[getStateDimension()] : entry.getValue();
121 }
122
123 /** Convert a flattened array to a square matrix.
124 * @param array input array
125 * @return the corresponding matrix
126 * @since 13.1
127 */
128 public RealMatrix toSquareMatrix(final double[] array) {
129 final int stateDimension = getStateDimension();
130 final RealMatrix matrix = MatrixUtils.createRealMatrix(stateDimension, stateDimension);
131 int index = 0;
132 for (int i = 0; i < stateDimension; ++i) {
133 for (int j = 0; j < stateDimension; ++j) {
134 matrix.setEntry(i, j, array[index++]);
135 }
136 }
137 return matrix;
138 }
139
140 /** Set the STM data into an array.
141 * @param matrix STM matrix
142 * @return an array containing the STM data
143 * @since 13.1
144 */
145 public double[] toArray(final double[][] matrix) {
146 final int stateDimension = matrix.length;
147 final double[] array = new double[stateDimension * stateDimension];
148 int index = 0;
149 for (final double[] row : matrix) {
150 for (int j = 0; j < stateDimension; ++j) {
151 array[index++] = row[j];
152 }
153 }
154 return array;
155 }
156
157 /** {@inheritDoc} */
158 @Override
159 public void setReferenceState(final SpacecraftState reference) {
160 // nothing to do
161 }
162
163 /** Freeze the names of the Jacobian columns.
164 * <p>
165 * This method is called when propagation starts, i.e. when configuration is completed
166 * </p>
167 */
168 public abstract void freezeColumnsNames();
169
170 }