1   /* Copyright 2002-2026 CS GROUP
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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
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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
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16   */
17  package org.orekit.propagation.semianalytical.dsst.utilities;
18  
19  import org.hipparchus.CalculusFieldElement;
20  
21  /**  Interface for interpolation grids.
22   * <p>
23   * An interpolation grid provides a grid of time points
24   * that can be used for interpolation processes.
25   * </p>
26   * <p>
27   * In the context of DSST propagation, an interpolation grid is used for the
28   * computation through interpolation of short periodics coefficients
29   * </p>
30   * @author Nicolas Bernard
31   */
32  public interface InterpolationGrid {
33  
34      /** Get grid points that are within the current step.
35       * <p>The step is defined by its start and its end time.
36       * </p>
37       * @param stepStart start of the step
38       * @param stepEnd end of the step
39       * @return time points between start and end
40       */
41      double[] getGridPoints(double stepStart, double stepEnd);
42  
43      /** Get grid points that are within the current step.
44       * <p>The step is defined by its start and its end time.
45       * </p>
46       * @param stepStart start of the step
47       * @param stepEnd end of the step
48       * @param <T> type of the elements
49       * @return time points between start and end
50       * @since 14.0
51       */
52      <T extends CalculusFieldElement<T>> T[] getGridPoints(T stepStart, T stepEnd);
53  }