1   /* Copyright 2022-2025 Romain Serra
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.conversion;
18  
19  import org.hipparchus.geometry.euclidean.threed.Vector3D;
20  import org.hipparchus.ode.ODEIntegrator;
21  import org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator;
22  import org.junit.jupiter.api.Assertions;
23  import org.junit.jupiter.api.Test;
24  import org.orekit.frames.FramesFactory;
25  import org.orekit.orbits.CartesianOrbit;
26  import org.orekit.orbits.OrbitType;
27  import org.orekit.time.AbsoluteDate;
28  import org.orekit.utils.AbsolutePVCoordinates;
29  
30  class ClassicalRungeKuttaIntegratorBuilderTest {
31  
32      @Test
33      void testBuildIntegrator() {
34          // GIVEN
35          final AbsolutePVCoordinates absolutePVCoordinates = new AbsolutePVCoordinates(FramesFactory.getGCRF(),
36                  AbsoluteDate.ARBITRARY_EPOCH, Vector3D.MINUS_I, Vector3D.MINUS_K);
37          final double step = 10;
38          final ClassicalRungeKuttaIntegratorBuilder builder = new ClassicalRungeKuttaIntegratorBuilder(step);
39          // WHEN
40          final ODEIntegrator integrator = builder.buildIntegrator(absolutePVCoordinates);
41          // THEN
42          final ClassicalRungeKuttaIntegrator actualIntegrator = (ClassicalRungeKuttaIntegrator) integrator;
43          final CartesianOrbit orbit = new CartesianOrbit(absolutePVCoordinates.getPVCoordinates(), absolutePVCoordinates.getFrame(),
44                  absolutePVCoordinates.getDate(), 1.);
45          final ClassicalRungeKuttaIntegrator expectedIntegrator = (ClassicalRungeKuttaIntegrator) builder.buildIntegrator(orbit, OrbitType.CARTESIAN);
46          Assertions.assertEquals(expectedIntegrator.getCurrentSignedStepsize(), actualIntegrator.getCurrentSignedStepsize());
47      }
48  
49  }