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.analytical;
18  
19  import org.hipparchus.analysis.differentiation.Gradient;
20  import org.orekit.propagation.SpacecraftState;
21  import org.orekit.propagation.integration.AbstractGradientConverter;
22  import org.orekit.utils.ParameterDriversProvider;
23  
24  /**
25   * Converter for analytical orbit propagator.
26   *
27   * @author Bryan Cazabonne
28   * @since 11.1
29   */
30  public abstract class AbstractAnalyticalGradientConverter
31      extends AbstractGradientConverter implements ParameterDriversProvider {
32  
33      /**
34       * Constructor.
35       * @param propagator analytical orbit propagator
36       * @param freeStateParameters number of free parameters
37       */
38      protected AbstractAnalyticalGradientConverter(final AbstractAnalyticalPropagator propagator,
39                                                    final int freeStateParameters) {
40          super(freeStateParameters);
41  
42          // get the initial state *without additional data*, in order to prevent infinite recursion
43          final SpacecraftState baseInitialState = propagator.getBaseInitialState();
44  
45          initStates(buildBasicGradientSpacecraftState(baseInitialState, freeStateParameters,
46                                                       freeStateParameters > 3 ? propagator.getAttitudeProvider() : null));
47  
48      }
49  
50      /**
51       * Get the converted analytical orbit propagator.
52       * @return the converted analytical orbit propagator
53       */
54      public abstract FieldAbstractAnalyticalPropagator<Gradient> getPropagator();
55  
56  }