1   /* Copyright 2002-2025 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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14   * See the License for the specific language governing permissions and
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16   */
17  package org.orekit.utils;
18  
19  import org.hipparchus.analysis.differentiation.DerivativeStructure;
20  import org.hipparchus.analysis.differentiation.UnivariateDerivative1;
21  import org.hipparchus.analysis.differentiation.UnivariateDerivative2;
22  import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
23  import org.hipparchus.geometry.euclidean.threed.Vector3D;
24  import org.junit.jupiter.api.Assertions;
25  import org.junit.jupiter.api.BeforeEach;
26  import org.junit.jupiter.api.Test;
27  import org.orekit.Utils;
28  import org.orekit.errors.OrekitIllegalArgumentException;
29  import org.orekit.errors.OrekitMessages;
30  import org.orekit.frames.Frame;
31  import org.orekit.frames.FramesFactory;
32  import org.orekit.frames.Transform;
33  import org.orekit.time.AbsoluteDate;
34  
35  public class AbsolutePVCoordinatesTest {
36  
37      @BeforeEach
38      public void setUp() {
39          Utils.setDataRoot("regular-data");
40      }
41  
42      @Test
43      public void testPVOnlyConstructor() {
44          //setup
45          AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
46          Frame frame = FramesFactory.getEME2000();
47          Vector3D p = new Vector3D(1, 2, 3);
48          Vector3D v = new Vector3D(4, 5, 6);
49  
50          //action
51          AbsolutePVCoordinates actual = new AbsolutePVCoordinates(frame, date, p, v);
52  
53          //verify
54          Assertions.assertEquals(date, actual.getDate());
55          Assertions.assertEquals(1, actual.getPosition().getX(), 0);
56          Assertions.assertEquals(2, actual.getPosition().getY(), 0);
57          Assertions.assertEquals(3, actual.getPosition().getZ(), 0);
58          Assertions.assertEquals(4, actual.getVelocity().getX(), 0);
59          Assertions.assertEquals(5, actual.getVelocity().getY(), 0);
60          Assertions.assertEquals(6, actual.getVelocity().getZ(), 0);
61          Assertions.assertEquals(Vector3D.ZERO, actual.getAcceleration());
62      }
63  
64      @Test
65      public void testPVCoordinatesCopyConstructor() {
66          //setup
67          AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
68          Frame frame = FramesFactory.getEME2000();
69          PVCoordinates pv = new PVCoordinates(new Vector3D(1, 2, 3), new Vector3D(4, 5, 6));
70  
71          //action
72          AbsolutePVCoordinates actual = new AbsolutePVCoordinates(frame, date, pv);
73  
74          //verify
75          Assertions.assertEquals(date, actual.getDate());
76          Assertions.assertEquals(1, actual.getPosition().getX(), 0);
77          Assertions.assertEquals(2, actual.getPosition().getY(), 0);
78          Assertions.assertEquals(3, actual.getPosition().getZ(), 0);
79          Assertions.assertEquals(4, actual.getVelocity().getX(), 0);
80          Assertions.assertEquals(5, actual.getVelocity().getY(), 0);
81          Assertions.assertEquals(6, actual.getVelocity().getZ(), 0);
82          Assertions.assertEquals(Vector3D.ZERO, actual.getAcceleration());
83      }
84  
85      @Test
86      public void testLinearConstructors() {
87          Frame frame = FramesFactory.getEME2000();
88          AbsolutePVCoordinates pv1 = new AbsolutePVCoordinates(frame,
89                                                                AbsoluteDate.CCSDS_EPOCH,
90                                                                new Vector3D( 1,  0.1,   10),
91                                                                new Vector3D(-1, -0.1,  -10),
92                                                                new Vector3D(10, -1.0, -100));
93          AbsolutePVCoordinates pv2 = new AbsolutePVCoordinates(frame,
94                                                                AbsoluteDate.FIFTIES_EPOCH,
95                                                                new Vector3D( 2,  0.2,   20),
96                                                                new Vector3D(-2, -0.2,  -20),
97                                                                new Vector3D(20, -2.0, -200));
98          AbsolutePVCoordinates pv3 = new AbsolutePVCoordinates(frame,
99                                                                AbsoluteDate.GALILEO_EPOCH,
100                                                               new Vector3D( 3,  0.3,   30),
101                                                               new Vector3D(-3, -0.3,  -30),
102                                                               new Vector3D(30, -3.0, -300));
103         AbsolutePVCoordinates pv4 = new AbsolutePVCoordinates(frame,
104                                                               AbsoluteDate.JULIAN_EPOCH,
105                                                               new Vector3D( 4,  0.4,   40),
106                                                               new Vector3D(-4, -0.4,  -40),
107                                                               new Vector3D(40, -4.0, -400));
108         assertPV(pv4, new AbsolutePVCoordinates(AbsoluteDate.JULIAN_EPOCH, 4, pv1), 1.0e-15);
109         assertPV(pv2, new AbsolutePVCoordinates(AbsoluteDate.FIFTIES_EPOCH, pv1, pv3), 1.0e-15);
110         assertPV(pv3, new AbsolutePVCoordinates(AbsoluteDate.GALILEO_EPOCH, 1, pv1, 1, pv2), 1.0e-15);
111         assertPV(new AbsolutePVCoordinates(AbsoluteDate.J2000_EPOCH, 2, pv4),
112                  new AbsolutePVCoordinates(AbsoluteDate.J2000_EPOCH, 3, pv1, 1, pv2, 1, pv3),
113                  1.0e-15);
114         assertPV(new AbsolutePVCoordinates(AbsoluteDate.J2000_EPOCH, 3, pv3),
115                  new AbsolutePVCoordinates(AbsoluteDate.J2000_EPOCH, 3, pv1, 1, pv2, 1, pv4),
116                  1.0e-15);
117         assertPV(new AbsolutePVCoordinates(AbsoluteDate.J2000_EPOCH, 5, pv4),
118                  new AbsolutePVCoordinates(AbsoluteDate.J2000_EPOCH, 4, pv1, 3, pv2, 2, pv3, 1, pv4),
119                  1.0e-15);
120     }
121 
122     @Test
123     public void testDifferentFrames() {
124         final AbsolutePVCoordinates apv1 = new AbsolutePVCoordinates(FramesFactory.getEME2000(),
125                                                                      AbsoluteDate.ARBITRARY_EPOCH,
126                                                                      Vector3D.ZERO, Vector3D.ZERO, Vector3D.ZERO);
127         final AbsolutePVCoordinates apv2 = new AbsolutePVCoordinates(FramesFactory.getGCRF(),
128                                                                      AbsoluteDate.ARBITRARY_EPOCH,
129                                                                      Vector3D.ZERO, Vector3D.ZERO, Vector3D.ZERO);
130         try {
131             new AbsolutePVCoordinates(AbsoluteDate.ARBITRARY_EPOCH, apv1, apv2);
132             Assertions.fail("an exception should have been thrown");
133         } catch (OrekitIllegalArgumentException oe) {
134             Assertions.assertEquals(OrekitMessages.INCOMPATIBLE_FRAMES, oe.getSpecifier());
135             Assertions.assertEquals(apv1.getFrame().getName(), oe.getParts()[0]);
136             Assertions.assertEquals(apv2.getFrame().getName(), oe.getParts()[1]);
137         }
138     }
139 
140     @Test
141     public void testToDerivativeStructureVector1() {
142         FieldVector3D<DerivativeStructure> fv =
143                 new AbsolutePVCoordinates(FramesFactory.getEME2000(),
144                                           AbsoluteDate.GALILEO_EPOCH,
145                                           new Vector3D( 1,  0.1,  10),
146                                           new Vector3D(-1, -0.1, -10),
147                                           new Vector3D(10, -1.0, -100)).toDerivativeStructureVector(1);
148         Assertions.assertEquals(1, fv.getX().getFreeParameters());
149         Assertions.assertEquals(1, fv.getX().getOrder());
150         Assertions.assertEquals(   1.0, fv.getX().getReal(), 1.0e-10);
151         Assertions.assertEquals(   0.1, fv.getY().getReal(), 1.0e-10);
152         Assertions.assertEquals(  10.0, fv.getZ().getReal(), 1.0e-10);
153         Assertions.assertEquals(  -1.0, fv.getX().getPartialDerivative(1), 1.0e-15);
154         Assertions.assertEquals(  -0.1, fv.getY().getPartialDerivative(1), 1.0e-15);
155         Assertions.assertEquals( -10.0, fv.getZ().getPartialDerivative(1), 1.0e-15);
156         assertPV(new AbsolutePVCoordinates(FramesFactory.getEME2000(),
157                                            AbsoluteDate.GALILEO_EPOCH,
158                                            new Vector3D( 1,  0.1,  10),
159                                            new Vector3D(-1, -0.1, -10),
160                                            Vector3D.ZERO),
161                  new AbsolutePVCoordinates(FramesFactory.getEME2000(),
162                                           AbsoluteDate.GALILEO_EPOCH, fv), 1.0e-15);
163 
164         for (double dt = 0; dt < 10; dt += 0.125) {
165             Vector3D p = new PVCoordinates(new Vector3D( 1,  0.1,  10),
166                                            new Vector3D(-1, -0.1, -10)).shiftedBy(dt).getPosition();
167             Assertions.assertEquals(p.getX(), fv.getX().taylor(dt), 1.0e-14);
168             Assertions.assertEquals(p.getY(), fv.getY().taylor(dt), 1.0e-14);
169             Assertions.assertEquals(p.getZ(), fv.getZ().taylor(dt), 1.0e-14);
170         }
171 
172         AbsolutePVCoordinates pv = new AbsolutePVCoordinates(FramesFactory.getEME2000(),
173                                                              AbsoluteDate.GALILEO_EPOCH,
174                                                              fv);
175         Assertions.assertEquals(   1.0, pv.getPosition().getX(), 1.0e-10);
176         Assertions.assertEquals(   0.1, pv.getPosition().getY(), 1.0e-10);
177         Assertions.assertEquals(  10.0, pv.getPosition().getZ(), 1.0e-10);
178         Assertions.assertEquals(  -1.0, pv.getVelocity().getX(), 1.0e-15);
179         Assertions.assertEquals(  -0.1, pv.getVelocity().getY(), 1.0e-15);
180         Assertions.assertEquals( -10.0, pv.getVelocity().getZ(), 1.0e-15);
181 
182     }
183 
184     @Test
185     public void testToDerivativeStructureVector2() {
186         FieldVector3D<DerivativeStructure> fv =
187                 new AbsolutePVCoordinates(FramesFactory.getEME2000(),
188                                           AbsoluteDate.GALILEO_EPOCH,
189                                           new Vector3D( 1,  0.1,  10),
190                                           new Vector3D(-1, -0.1, -10),
191                                           new Vector3D(10, -1.0, -100)).toDerivativeStructureVector(2);
192         Assertions.assertEquals(1, fv.getX().getFreeParameters());
193         Assertions.assertEquals(2, fv.getX().getOrder());
194         Assertions.assertEquals(   1.0, fv.getX().getReal(), 1.0e-10);
195         Assertions.assertEquals(   0.1, fv.getY().getReal(), 1.0e-10);
196         Assertions.assertEquals(  10.0, fv.getZ().getReal(), 1.0e-10);
197         Assertions.assertEquals(  -1.0, fv.getX().getPartialDerivative(1), 1.0e-15);
198         Assertions.assertEquals(  -0.1, fv.getY().getPartialDerivative(1), 1.0e-15);
199         Assertions.assertEquals( -10.0, fv.getZ().getPartialDerivative(1), 1.0e-15);
200         Assertions.assertEquals(  10.0, fv.getX().getPartialDerivative(2), 1.0e-15);
201         Assertions.assertEquals(  -1.0, fv.getY().getPartialDerivative(2), 1.0e-15);
202         Assertions.assertEquals(-100.0, fv.getZ().getPartialDerivative(2), 1.0e-15);
203         assertPV(new AbsolutePVCoordinates(FramesFactory.getEME2000(),
204                                            AbsoluteDate.GALILEO_EPOCH,
205                                            new Vector3D( 1,  0.1,  10),
206                                            new Vector3D(-1, -0.1, -10),
207                                            new Vector3D(10, -1.0, -100)),
208                  new AbsolutePVCoordinates(FramesFactory.getEME2000(),
209                                           AbsoluteDate.GALILEO_EPOCH, fv), 1.0e-15);
210 
211         for (double dt = 0; dt < 10; dt += 0.125) {
212             Vector3D p = new PVCoordinates(new Vector3D( 1,  0.1,  10),
213                                            new Vector3D(-1, -0.1, -10),
214                                            new Vector3D(10, -1.0, -100)).shiftedBy(dt).getPosition();
215             Assertions.assertEquals(p.getX(), fv.getX().taylor(dt), 1.0e-14);
216             Assertions.assertEquals(p.getY(), fv.getY().taylor(dt), 1.0e-14);
217             Assertions.assertEquals(p.getZ(), fv.getZ().taylor(dt), 1.0e-14);
218         }
219 
220         AbsolutePVCoordinates pv = new AbsolutePVCoordinates(FramesFactory.getEME2000(),
221                                                              AbsoluteDate.GALILEO_EPOCH,
222                                                              fv);
223         Assertions.assertEquals(   1.0, pv.getPosition().getX(), 1.0e-10);
224         Assertions.assertEquals(   0.1, pv.getPosition().getY(), 1.0e-10);
225         Assertions.assertEquals(  10.0, pv.getPosition().getZ(), 1.0e-10);
226         Assertions.assertEquals(  -1.0, pv.getVelocity().getX(), 1.0e-15);
227         Assertions.assertEquals(  -0.1, pv.getVelocity().getY(), 1.0e-15);
228         Assertions.assertEquals( -10.0, pv.getVelocity().getZ(), 1.0e-15);
229         Assertions.assertEquals(  10.0, pv.getAcceleration().getX(), 1.0e-15);
230         Assertions.assertEquals(  -1.0, pv.getAcceleration().getY(), 1.0e-15);
231         Assertions.assertEquals(-100.0, pv.getAcceleration().getZ(), 1.0e-15);
232 
233     }
234 
235     @Test
236     public void testToUnivariateDerivative1Vector() {
237         FieldVector3D<UnivariateDerivative1> fv =
238                 new AbsolutePVCoordinates(FramesFactory.getEME2000(),
239                                           AbsoluteDate.GALILEO_EPOCH,
240                                           new Vector3D( 1,  0.1,  10),
241                                           new Vector3D(-1, -0.1, -10),
242                                           new Vector3D(10, -1.0, -100)).toUnivariateDerivative1Vector();
243         Assertions.assertEquals(1, fv.getX().getFreeParameters());
244         Assertions.assertEquals(1, fv.getX().getOrder());
245         Assertions.assertEquals(   1.0, fv.getX().getReal(), 1.0e-10);
246         Assertions.assertEquals(   0.1, fv.getY().getReal(), 1.0e-10);
247         Assertions.assertEquals(  10.0, fv.getZ().getReal(), 1.0e-10);
248         Assertions.assertEquals(  -1.0, fv.getX().getPartialDerivative(1), 1.0e-15);
249         Assertions.assertEquals(  -0.1, fv.getY().getPartialDerivative(1), 1.0e-15);
250         Assertions.assertEquals( -10.0, fv.getZ().getPartialDerivative(1), 1.0e-15);
251         assertPV(new AbsolutePVCoordinates(FramesFactory.getEME2000(),
252                                            AbsoluteDate.GALILEO_EPOCH,
253                                            new Vector3D( 1,  0.1,  10),
254                                            new Vector3D(-1, -0.1, -10),
255                                            Vector3D.ZERO),
256                  new AbsolutePVCoordinates(FramesFactory.getEME2000(),
257                                           AbsoluteDate.GALILEO_EPOCH, fv), 1.0e-15);
258 
259         for (double dt = 0; dt < 10; dt += 0.125) {
260             Vector3D p = new PVCoordinates(new Vector3D( 1,  0.1,  10),
261                                            new Vector3D(-1, -0.1, -10)).shiftedBy(dt).getPosition();
262             Assertions.assertEquals(p.getX(), fv.getX().taylor(dt), 1.0e-14);
263             Assertions.assertEquals(p.getY(), fv.getY().taylor(dt), 1.0e-14);
264             Assertions.assertEquals(p.getZ(), fv.getZ().taylor(dt), 1.0e-14);
265         }
266 
267         AbsolutePVCoordinates pv = new AbsolutePVCoordinates(FramesFactory.getEME2000(),
268                                                              AbsoluteDate.GALILEO_EPOCH,
269                                                              fv);
270         Assertions.assertEquals(   1.0, pv.getPosition().getX(), 1.0e-10);
271         Assertions.assertEquals(   0.1, pv.getPosition().getY(), 1.0e-10);
272         Assertions.assertEquals(  10.0, pv.getPosition().getZ(), 1.0e-10);
273         Assertions.assertEquals(  -1.0, pv.getVelocity().getX(), 1.0e-15);
274         Assertions.assertEquals(  -0.1, pv.getVelocity().getY(), 1.0e-15);
275         Assertions.assertEquals( -10.0, pv.getVelocity().getZ(), 1.0e-15);
276 
277     }
278 
279     @Test
280     public void testToUnivariateDerivative2Vector() {
281         FieldVector3D<UnivariateDerivative2> fv =
282                 new AbsolutePVCoordinates(FramesFactory.getEME2000(),
283                                           AbsoluteDate.GALILEO_EPOCH,
284                                           new Vector3D( 1,  0.1,  10),
285                                           new Vector3D(-1, -0.1, -10),
286                                           new Vector3D(10, -1.0, -100)).toUnivariateDerivative2Vector();
287         Assertions.assertEquals(1, fv.getX().getFreeParameters());
288         Assertions.assertEquals(2, fv.getX().getOrder());
289         Assertions.assertEquals(   1.0, fv.getX().getReal(), 1.0e-10);
290         Assertions.assertEquals(   0.1, fv.getY().getReal(), 1.0e-10);
291         Assertions.assertEquals(  10.0, fv.getZ().getReal(), 1.0e-10);
292         Assertions.assertEquals(  -1.0, fv.getX().getPartialDerivative(1), 1.0e-15);
293         Assertions.assertEquals(  -0.1, fv.getY().getPartialDerivative(1), 1.0e-15);
294         Assertions.assertEquals( -10.0, fv.getZ().getPartialDerivative(1), 1.0e-15);
295         Assertions.assertEquals(  10.0, fv.getX().getPartialDerivative(2), 1.0e-15);
296         Assertions.assertEquals(  -1.0, fv.getY().getPartialDerivative(2), 1.0e-15);
297         Assertions.assertEquals(-100.0, fv.getZ().getPartialDerivative(2), 1.0e-15);
298         assertPV(new AbsolutePVCoordinates(FramesFactory.getEME2000(),
299                                            AbsoluteDate.GALILEO_EPOCH,
300                                            new Vector3D( 1,  0.1,  10),
301                                            new Vector3D(-1, -0.1, -10),
302                                            new Vector3D(10, -1.0, -100)),
303                  new AbsolutePVCoordinates(FramesFactory.getEME2000(),
304                                           AbsoluteDate.GALILEO_EPOCH, fv), 1.0e-15);
305 
306         for (double dt = 0; dt < 10; dt += 0.125) {
307             Vector3D p = new PVCoordinates(new Vector3D( 1,  0.1,  10),
308                                            new Vector3D(-1, -0.1, -10),
309                                            new Vector3D(10, -1.0, -100)).shiftedBy(dt).getPosition();
310             Assertions.assertEquals(p.getX(), fv.getX().taylor(dt), 1.0e-14);
311             Assertions.assertEquals(p.getY(), fv.getY().taylor(dt), 1.0e-14);
312             Assertions.assertEquals(p.getZ(), fv.getZ().taylor(dt), 1.0e-14);
313         }
314 
315         AbsolutePVCoordinates pv = new AbsolutePVCoordinates(FramesFactory.getEME2000(),
316                                                              AbsoluteDate.GALILEO_EPOCH,
317                                                              fv);
318         Assertions.assertEquals(   1.0, pv.getPosition().getX(), 1.0e-10);
319         Assertions.assertEquals(   0.1, pv.getPosition().getY(), 1.0e-10);
320         Assertions.assertEquals(  10.0, pv.getPosition().getZ(), 1.0e-10);
321         Assertions.assertEquals(  -1.0, pv.getVelocity().getX(), 1.0e-15);
322         Assertions.assertEquals(  -0.1, pv.getVelocity().getY(), 1.0e-15);
323         Assertions.assertEquals( -10.0, pv.getVelocity().getZ(), 1.0e-15);
324         Assertions.assertEquals(  10.0, pv.getAcceleration().getX(), 1.0e-15);
325         Assertions.assertEquals(  -1.0, pv.getAcceleration().getY(), 1.0e-15);
326         Assertions.assertEquals(-100.0, pv.getAcceleration().getZ(), 1.0e-15);
327 
328     }
329 
330     @Test
331     public void testShift() {
332         Vector3D p1 = new Vector3D(  1,  0.1,   10);
333         Vector3D v1 = new Vector3D( -1, -0.1,  -10);
334         Vector3D a1 = new Vector3D( 10,  1.0,  100);
335         Vector3D p2 = new Vector3D(  7,  0.7,   70);
336         Vector3D v2 = new Vector3D(-11, -1.1, -110);
337         Vector3D a2 = new Vector3D( 10,  1.0,  100);
338         assertPV(new AbsolutePVCoordinates(FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH, p2, v2, a2),
339                  new AbsolutePVCoordinates(FramesFactory.getEME2000(), AbsoluteDate.J2000_EPOCH.shiftedBy(1.0), p1, v1, a1).shiftedBy(-1.0), 1.0e-15);
340         Assertions.assertEquals(0.0, AbsolutePVCoordinates.estimateVelocity(p1, p2, -1.0).subtract(new Vector3D(-6, -0.6, -60)).getNorm(), 1.0e-15);
341     }
342 
343     @Test
344     public void testToString() {
345         AbsolutePVCoordinates pv =
346             new AbsolutePVCoordinates(FramesFactory.getEME2000(),
347                                       AbsoluteDate.J2000_EPOCH,
348                                       new Vector3D( 1,   0.1,  10),
349                                       new Vector3D(-1,  -0.1, -10),
350                                       new Vector3D(10,   1.0, 100));
351         Assertions.assertEquals("{2000-01-01T11:58:55.816, P(1.0, 0.1, 10.0), V(-1.0, -0.1, -10.0), A(10.0, 1.0, 100.0)}", pv.toString());
352     }
353 
354     @Test
355     public void testSamePV() {
356         //setup
357         AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
358         Frame frame = FramesFactory.getEME2000();
359         Vector3D p = new Vector3D(1, 2, 3);
360         Vector3D v = new Vector3D(4, 5, 6);
361         Frame otherEme2000 = new Frame(frame, Transform.IDENTITY, "other-EME2000");
362 
363         //action
364         AbsolutePVCoordinates actual = new AbsolutePVCoordinates(frame, date, p, v);
365 
366         //verify
367         Assertions.assertSame(actual.getPosition(), actual.getPosition(frame));
368         Assertions.assertNotSame(actual.getPosition(), actual.getPosition(otherEme2000));
369         Assertions.assertEquals(0.0,
370                                 Vector3D.distance(actual.getPosition(frame),
371                                                   actual.getPosition(otherEme2000)),
372                                 1.0e-15);
373         Assertions.assertEquals(0.0,
374                                 Vector3D.distance(actual.getPVCoordinates(frame).getPosition(),
375                                                   actual.getPVCoordinates(date, frame).getPosition()),
376                                 1.0e-15);
377         Assertions.assertEquals(0.0,
378                                 Vector3D.distance(actual.getPVCoordinates(frame).getVelocity(),
379                                                   actual.getPVCoordinates(date, frame).getVelocity()),
380                                 1.0e-15);
381         Assertions.assertEquals(0.0,
382                                 Vector3D.distance(actual.getPVCoordinates(frame).getAcceleration(),
383                                                   actual.getPVCoordinates(date, frame).getAcceleration()),
384                                 1.0e-15);
385         Assertions.assertEquals(0.0,
386                                 Vector3D.distance(actual.getPVCoordinates(frame).getPosition(),
387                                                   actual.getPVCoordinates(date, otherEme2000).getPosition()),
388                                 1.0e-15);
389         Assertions.assertEquals(0.0,
390                                 Vector3D.distance(actual.getPVCoordinates(frame).getVelocity(),
391                                                   actual.getPVCoordinates(date, otherEme2000).getVelocity()),
392                                 1.0e-15);
393         Assertions.assertEquals(0.0,
394                                 Vector3D.distance(actual.getPVCoordinates(frame).getAcceleration(),
395                                                   actual.getPVCoordinates(date, otherEme2000).getAcceleration()),
396                                 1.0e-15);
397     }
398 
399     @Test
400     public void testTaylorProvider() {
401         //setup
402         AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
403         Frame frame = FramesFactory.getEME2000();
404         Vector3D p = new Vector3D(1, 2, 3);
405         Vector3D v = new Vector3D(4, 5, 6);
406 
407         //action
408         AbsolutePVCoordinates actual = new AbsolutePVCoordinates(frame, date, p, v);
409         final PVCoordinatesProvider pv = actual.toTaylorProvider();
410 
411         //verify 
412         Assertions.assertEquals(0.0,
413                                 Vector3D.distance(actual.getPosition(date, frame), pv.getPosition(date, frame)),
414                                 1.0e-15);
415         Assertions.assertEquals(actual.getPVCoordinates(date, frame).toString(), pv.getPVCoordinates(date, frame).toString());
416 
417     }
418 
419     public static void assertPV(TimeStampedPVCoordinates expected, TimeStampedPVCoordinates real, double epsilon) {
420         Assertions.assertTrue(expected.getDate().isCloseTo(real.getDate(), epsilon));
421         Assertions.assertEquals(expected.getPosition().getX(), real.getPosition().getX(), epsilon);
422         Assertions.assertEquals(expected.getPosition().getY(), real.getPosition().getY(), epsilon);
423         Assertions.assertEquals(expected.getPosition().getZ(), real.getPosition().getZ(), epsilon);
424         Assertions.assertEquals(expected.getVelocity().getX(), real.getVelocity().getX(), epsilon);
425         Assertions.assertEquals(expected.getVelocity().getY(), real.getVelocity().getY(), epsilon);
426         Assertions.assertEquals(expected.getVelocity().getZ(), real.getVelocity().getZ(), epsilon);
427         Assertions.assertEquals(expected.getAcceleration().getX(), real.getAcceleration().getX(), epsilon);
428         Assertions.assertEquals(expected.getAcceleration().getY(), real.getAcceleration().getY(), epsilon);
429         Assertions.assertEquals(expected.getAcceleration().getZ(), real.getAcceleration().getZ(), epsilon);
430     }
431 
432 }