1   /* Copyright 2002-2019 CS Systèmes d'Information
2    * Licensed to CS Systèmes d'Information (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  /** This interface represents providers for additional state data beyond {@link SpacecraftState}.
20   * <p>
21   * This interface is the analytical (read already integrated) counterpart of
22   * the {@link org.orekit.propagation.integration.AdditionalEquations} interface.
23   * It allows to append various additional state parameters to any {@link
24   * org.orekit.propagation.AbstractPropagator abstract propagator}.
25   * </p>
26   * @see org.orekit.propagation.AbstractPropagator
27   * @see org.orekit.propagation.integration.AdditionalEquations
28   * @author Luc Maisonobe
29   */
30  public interface AdditionalStateProvider {
31  
32      /** Get the name of the additional state.
33       * @return name of the additional state
34       */
35      String getName();
36  
37      /** Get the additional state.
38       * @param state spacecraft state to which additional state should correspond
39       * @return additional state corresponding to spacecraft state
40       */
41      double[] getAdditionalState(SpacecraftState state);
42  
43  }