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.numerical;
18  
19  import org.hipparchus.analysis.differentiation.Gradient;
20  import org.orekit.attitudes.AttitudeProvider;
21  import org.orekit.propagation.FieldSpacecraftState;
22  import org.orekit.propagation.SpacecraftState;
23  import org.orekit.propagation.AbstractGradientConverter;
24  import org.orekit.utils.FieldDataDictionary;
25  
26  /** Converter for states and parameters arrays.
27   * @author Luc Maisonobe
28   * @since 10.2
29   */
30  class NumericalGradientConverter extends AbstractGradientConverter {
31  
32  
33      /** Constructor.
34       * @param state regular state
35       * @param freeStateParameters number of free parameters, either 3 (position) or 6 (position-velocity)
36       * @param provider provider to use if attitude needs to be recomputed
37       * @param keepAdditionalData flag to keep additional data
38       * @since 13.1.8
39       */
40      NumericalGradientConverter(final SpacecraftState state, final int freeStateParameters,
41                                 final AttitudeProvider provider, final boolean keepAdditionalData) {
42  
43          super(freeStateParameters);
44  
45          // initialize the list with the state having 0 force model parameters
46          final AttitudeProvider passedAttitudeProvider = freeStateParameters > 3 ? provider : null;
47          final FieldSpacecraftState<Gradient> basicGradientState = buildBasicGradientSpacecraftState(state,
48                  freeStateParameters, passedAttitudeProvider);
49          initStates(keepAdditionalData ? basicGradientState.withAdditionalData(new FieldDataDictionary<>(basicGradientState.getMass().getField(), state.getAdditionalDataValues().toMap())) : basicGradientState);
50      }
51  
52      /** Simple constructor with default values.
53       * @param state regular state
54       * @param freeStateParameters number of free parameters, either 3 (position) or 6 (position-velocity)
55       * @param provider provider to use if attitude needs to be recomputed
56       */
57      NumericalGradientConverter(final SpacecraftState state, final int freeStateParameters,
58                                 final AttitudeProvider provider) {
59          this(state, freeStateParameters, provider, false);
60      }
61  
62  }