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23 package org.hipparchus.migration.ode;
24
25 import java.lang.reflect.Constructor;
26 import java.lang.reflect.InvocationTargetException;
27 import java.util.Random;
28
29 import org.hipparchus.exception.MathIllegalArgumentException;
30 import org.hipparchus.exception.MathIllegalStateException;
31 import org.hipparchus.ode.EquationsMapper;
32 import org.hipparchus.ode.ExpandableODE;
33 import org.hipparchus.ode.ODEIntegrator;
34 import org.hipparchus.ode.ODEState;
35 import org.hipparchus.ode.ODEStateAndDerivative;
36 import org.hipparchus.ode.TestProblem3;
37 import org.hipparchus.ode.nonstiff.DormandPrince54Integrator;
38 import org.hipparchus.ode.nonstiff.DormandPrince853Integrator;
39 import org.hipparchus.ode.sampling.DummyStepInterpolator;
40 import org.hipparchus.ode.sampling.ODEStateInterpolator;
41 import org.hipparchus.util.FastMath;
42 import org.junit.After;
43 import org.junit.Assert;
44 import org.junit.Before;
45 import org.junit.Test;
46
47 @Deprecated
48 public class ContinuousOutputModelTest {
49
50 TestProblem3 pb;
51 ODEIntegrator integ;
52
53 @Test
54 public void testBoundaries() throws MathIllegalArgumentException, MathIllegalStateException {
55 integ.addStepHandler(new ContinuousOutputModel());
56 integ.integrate(pb, pb.getInitialState(), pb.getFinalTime());
57 ContinuousOutputModel cm = (ContinuousOutputModel) integ.getStepHandlers().iterator().next();
58 cm.setInterpolatedTime(2.0 * pb.getInitialTime() - pb.getFinalTime());
59 cm.setInterpolatedTime(2.0 * pb.getFinalTime() - pb.getInitialTime());
60 cm.setInterpolatedTime(0.5 * (pb.getFinalTime() + pb.getInitialTime()));
61 }
62
63 @Test
64 public void testRandomAccess() throws MathIllegalArgumentException, MathIllegalStateException {
65
66 ContinuousOutputModel cm = new ContinuousOutputModel();
67 integ.addStepHandler(cm);
68 integ.integrate(pb, pb.getInitialState(), pb.getFinalTime());
69
70 Random random = new Random(347588535632l);
71 double maxError = 0.0;
72 double maxErrorDot = 0.0;
73 for (int i = 0; i < 1000; ++i) {
74 double r = random.nextDouble();
75 double time = r * pb.getInitialTime() + (1.0 - r) * pb.getFinalTime();
76 cm.setInterpolatedTime(time);
77 double[] interpolatedY = cm.getInterpolatedState();
78 double[] interpolatedYDot = cm.getInterpolatedDerivatives();
79 double[] theoreticalY = pb.computeTheoreticalState(time);
80 double[] theoreticalYDot = pb.doComputeDerivatives(time, theoreticalY);
81 double dx = interpolatedY[0] - theoreticalY[0];
82 double dy = interpolatedY[1] - theoreticalY[1];
83 double error = dx * dx + dy * dy;
84 maxError = FastMath.max(maxError, error);
85 double dxDot = interpolatedYDot[0] - theoreticalYDot[0];
86 double dyDot = interpolatedYDot[1] - theoreticalYDot[1];
87 double errorDot = dxDot * dxDot + dyDot * dyDot;
88 maxErrorDot = FastMath.max(maxErrorDot, errorDot);
89 }
90
91 Assert.assertEquals(0.0, maxError, 1.0e-9);
92 Assert.assertEquals(0.0, maxErrorDot, 4.0e-7);
93
94 }
95
96 @Test
97 public void testModelsMerging() throws MathIllegalArgumentException, MathIllegalStateException {
98
99
100 FirstOrderDifferentialEquations problem =
101 new FirstOrderDifferentialEquations() {
102 @Override
103 public void computeDerivatives(double t, double[] y, double[] dot) {
104 dot[0] = -y[1];
105 dot[1] = y[0];
106 }
107 @Override
108 public int getDimension() {
109 return 2;
110 }
111 };
112
113
114 ContinuousOutputModel cm1 = new ContinuousOutputModel();
115 ODEIntegrator integ1 = new DormandPrince853Integrator(0, 1.0, 1.0e-8, 1.0e-8);
116 integ1.addStepHandler(cm1);
117 integ1.integrate(new ExpandableODE(problem),
118 new ODEState(FastMath.PI, new double[] { -1.0, 0.0 }),
119 0);
120
121
122 ContinuousOutputModel cm2 = new ContinuousOutputModel();
123 ODEIntegrator integ2 = new DormandPrince853Integrator(0, 0.1, 1.0e-12, 1.0e-12);
124 integ2.addStepHandler(cm2);
125 integ2.integrate(new ExpandableODE(problem),
126 new ODEState(2.0 * FastMath.PI, new double[] { 1.0, 0.0 }),
127 FastMath.PI);
128
129
130 ContinuousOutputModel cm = new ContinuousOutputModel();
131 cm.append(cm2);
132 cm.append(new ContinuousOutputModel());
133 cm.append(cm1);
134
135
136 Assert.assertEquals(2.0 * FastMath.PI, cm.getInitialTime(), 1.0e-12);
137 Assert.assertEquals(0, cm.getFinalTime(), 1.0e-12);
138 Assert.assertEquals(cm.getFinalTime(), cm.getInterpolatedTime(), 1.0e-12);
139 for (double t = 0; t < 2.0 * FastMath.PI; t += 0.1) {
140 cm.setInterpolatedTime(t);
141 double[] y = cm.getInterpolatedState();
142 Assert.assertEquals(FastMath.cos(t), y[0], 1.0e-7);
143 Assert.assertEquals(FastMath.sin(t), y[1], 1.0e-7);
144 }
145
146 }
147
148 @Test
149 public void testErrorConditions() throws MathIllegalArgumentException, MathIllegalStateException {
150
151 ContinuousOutputModel cm = new ContinuousOutputModel();
152 cm.handleStep(buildInterpolator(0, new double[] { 0.0, 1.0, -2.0 }, 1));
153
154
155 Assert.assertTrue(checkAppendError(cm, 1.0, new double[] { 0.0, 1.0 }, 2.0));
156
157
158 Assert.assertTrue(checkAppendError(cm, 10.0, new double[] { 0.0, 1.0, -2.0 }, 20.0));
159
160
161 Assert.assertTrue(checkAppendError(cm, 1.0, new double[] { 0.0, 1.0, -2.0 }, 0.0));
162
163
164 Assert.assertFalse(checkAppendError(cm, 1.0, new double[] { 0.0, 1.0, -2.0 }, 2.0));
165
166 }
167
168 private boolean checkAppendError(ContinuousOutputModel cm,
169 double t0, double[] y0, double t1)
170 throws MathIllegalArgumentException, MathIllegalStateException {
171 try {
172 ContinuousOutputModel otherCm = new ContinuousOutputModel();
173 otherCm.handleStep(buildInterpolator(t0, y0, t1));
174 cm.append(otherCm);
175 } catch(MathIllegalArgumentException iae) {
176 return true;
177 }
178 return false;
179 }
180
181 private ODEStateInterpolator buildInterpolator(double t0, double[] y0, double t1) {
182 EquationsMapper mapper = null;
183 try {
184 Constructor<EquationsMapper> ctr;
185 ctr = EquationsMapper.class.getDeclaredConstructor(EquationsMapper.class, Integer.TYPE);
186 ctr.setAccessible(true);
187 mapper = ctr.newInstance(null, y0.length);
188 } catch (NoSuchMethodException | SecurityException | InstantiationException |
189 IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
190 Assert.fail(e.getLocalizedMessage());
191 }
192 return new DummyStepInterpolator(t1 >= t0,
193 new ODEStateAndDerivative(t0, y0, new double[y0.length]),
194 new ODEStateAndDerivative(t1, y0, new double[y0.length]),
195 new ODEStateAndDerivative(t0, y0, new double[y0.length]),
196 new ODEStateAndDerivative(t1, y0, new double[y0.length]),
197 mapper);
198 }
199
200 public void checkValue(double value, double reference) {
201 Assert.assertTrue(FastMath.abs(value - reference) < 1.0e-10);
202 }
203
204 @Before
205 public void setUp() {
206 pb = new TestProblem3(0.9);
207 double minStep = 0;
208 double maxStep = pb.getFinalTime() - pb.getInitialTime();
209 integ = new DormandPrince54Integrator(minStep, maxStep, 1.0e-8, 1.0e-8);
210 }
211
212 @After
213 public void tearDown() {
214 pb = null;
215 integ = null;
216 }
217
218 }