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Added new consistency tests. 

We want the field-based integrators to be consistent with the regular
double-based integrators.
This commit is contained in:
Luc Maisonobe 2016-01-06 12:41:22 +01:00
parent c23335bae4
commit 235a0914e9
7 changed files with 152 additions and 2 deletions
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124
src/test/java/org/apache/commons/math4/ode/nonstiff/AbstractRungeKuttaFieldStepInterpolatorTest.java
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@ -22,10 +22,12 @@ import java.lang.reflect.InvocationTargetException;
import org.apache.commons.math4.Field;
import org.apache.commons.math4.RealFieldElement;
import org.apache.commons.math4.ode.EquationsMapper;
import org.apache.commons.math4.ode.FieldEquationsMapper;
import org.apache.commons.math4.ode.FieldExpandableODE;
import org.apache.commons.math4.ode.FieldFirstOrderDifferentialEquations;
import org.apache.commons.math4.ode.FieldODEStateAndDerivative;
import org.apache.commons.math4.ode.sampling.AbstractFieldStepInterpolator;
import org.apache.commons.math4.util.FastMath;
import org.apache.commons.math4.util.MathArrays;
import org.junit.Assert;
@ -86,6 +88,49 @@ public abstract class AbstractRungeKuttaFieldStepInterpolatorTest {
}
@Test
public abstract void nonFieldInterpolatorConsistency();
protected <T extends RealFieldElement<T>> void doNonFieldInterpolatorConsistency(final Field<T> field,
double epsilonSin, double epsilonCos,
double epsilonSinDot, double epsilonCosDot) {
RungeKuttaFieldStepInterpolator<T> fieldInterpolator =
setUpInterpolator(field, new SinCos<>(field), 0.0, new double[] { 0.0, 1.0 }, 0.125);
RungeKuttaStepInterpolator regularInterpolator = convertInterpolator(fieldInterpolator);
int n = 100;
double maxErrorSin = 0;
double maxErrorCos = 0;
double maxErrorSinDot = 0;
double maxErrorCosDot = 0;
for (int i = 0; i <= n; ++i) {
T t = fieldInterpolator.getPreviousState().getTime().multiply(n - i).
add(fieldInterpolator.getCurrentState().getTime().multiply(i)).
divide(n);
FieldODEStateAndDerivative<T> state = fieldInterpolator.getInterpolatedState(t);
T[] fieldY = state.getState();
T[] fieldYDot = state.getDerivative();
regularInterpolator.setInterpolatedTime(t.getReal());
double[] regularY = regularInterpolator.getInterpolatedState();
double[] regularYDot = regularInterpolator.getInterpolatedDerivatives();
maxErrorSin = FastMath.max(maxErrorSin, fieldY[0].subtract(regularY[0]).abs().getReal());
maxErrorCos = FastMath.max(maxErrorCos, fieldY[1].subtract(regularY[1]).abs().getReal());
maxErrorSinDot = FastMath.max(maxErrorSinDot, fieldYDot[0].subtract(regularYDot[0]).abs().getReal());
maxErrorCosDot = FastMath.max(maxErrorCosDot, fieldYDot[1].subtract(regularYDot[1]).abs().getReal());
}
Assert.assertEquals(0.0, maxErrorSin, epsilonSin);
Assert.assertEquals(0.0, maxErrorCos, epsilonCos);
Assert.assertEquals(0.0, maxErrorSinDot, epsilonSinDot);
Assert.assertEquals(0.0, maxErrorCosDot, epsilonCosDot);
}
private <T extends RealFieldElement<T>>
RungeKuttaFieldStepInterpolator<T> setUpInterpolator(final Field<T> field,
final FieldFirstOrderDifferentialEquations<T> eqn,
@ -139,6 +184,81 @@ public abstract class AbstractRungeKuttaFieldStepInterpolatorTest {
}
private <T extends RealFieldElement<T>>
RungeKuttaStepInterpolator convertInterpolator(final RungeKuttaFieldStepInterpolator<T> fieldInterpolator) {
RungeKuttaStepInterpolator regularInterpolator = null;
try {
String interpolatorName = fieldInterpolator.getClass().getName();
String integratorName = interpolatorName.replaceAll("Field", "");
@SuppressWarnings("unchecked")
Class<RungeKuttaStepInterpolator> clz = (Class<RungeKuttaStepInterpolator>) Class.forName(integratorName);
regularInterpolator = clz.newInstance();
double[][] yDotArray = null;
java.lang.reflect.Field fYD = RungeKuttaFieldStepInterpolator.class.getDeclaredField("yDotK");
fYD.setAccessible(true);
@SuppressWarnings("unchecked")
T[][] fieldYDotk = (T[][]) fYD.get(fieldInterpolator);
yDotArray = new double[fieldYDotk.length][];
for (int i = 0; i < yDotArray.length; ++i) {
yDotArray[i] = new double[fieldYDotk[i].length];
for (int j = 0; j < yDotArray[i].length; ++j) {
yDotArray[i][j] = fieldYDotk[i][j].getReal();
}
}
double[] y = new double[yDotArray[0].length];
EquationsMapper primaryMapper = null;
EquationsMapper[] secondaryMappers = null;
java.lang.reflect.Field fMapper = AbstractFieldStepInterpolator.class.getDeclaredField("mapper");
fMapper.setAccessible(true);
@SuppressWarnings("unchecked")
FieldEquationsMapper<T> mapper = (FieldEquationsMapper<T>) fMapper.get(fieldInterpolator);
java.lang.reflect.Field fStart = FieldEquationsMapper.class.getDeclaredField("start");
fStart.setAccessible(true);
int[] start = (int[]) fStart.get(mapper);
primaryMapper = new EquationsMapper(start[0], start[1]);
secondaryMappers = new EquationsMapper[mapper.getNumberOfEquations() - 1];
for (int i = 0; i < secondaryMappers.length; ++i) {
secondaryMappers[i] = new EquationsMapper(start[i + 1], start[i + 2]);
}
regularInterpolator.reinitialize(null, y, yDotArray,
fieldInterpolator.isForward(),
primaryMapper, secondaryMappers);
T[] fieldPreviousY = fieldInterpolator.getPreviousState().getState();
for (int i = 0; i < y.length; ++i) {
y[i] = fieldPreviousY[i].getReal();
}
regularInterpolator.storeTime(fieldInterpolator.getPreviousState().getTime().getReal());
regularInterpolator.shift();
T[] fieldCurrentY = fieldInterpolator.getCurrentState().getState();
for (int i = 0; i < y.length; ++i) {
y[i] = fieldCurrentY[i].getReal();
}
regularInterpolator.storeTime(fieldInterpolator.getCurrentState().getTime().getReal());
} catch (ClassNotFoundException cnfe) {
Assert.fail(cnfe.getLocalizedMessage());
} catch (InstantiationException ie) {
Assert.fail(ie.getLocalizedMessage());
} catch (IllegalAccessException iae) {
Assert.fail(iae.getLocalizedMessage());
} catch (NoSuchFieldException nsfe) {
Assert.fail(nsfe.getLocalizedMessage());
} catch (IllegalArgumentException iae) {
Assert.fail(iae.getLocalizedMessage());
}
return regularInterpolator;
}
private <T extends RealFieldElement<T>> RungeKuttaFieldIntegrator<T>
createFieldIntegrator(final Field<T> field, final RungeKuttaFieldStepInterpolator<T> interpolator) {
RungeKuttaFieldIntegrator<T> integrator = null;
@ -148,8 +268,8 @@ public abstract class AbstractRungeKuttaFieldStepInterpolatorTest {
@SuppressWarnings("unchecked")
Class<RungeKuttaFieldIntegrator<T>> clz = (Class<RungeKuttaFieldIntegrator<T>>) Class.forName(integratorName);
try {
integrator = clz.getConstructor(Field.class, RealFieldElement.class).newInstance(field,
field.getOne());
integrator = clz.getConstructor(Field.class, RealFieldElement.class).
newInstance(field, field.getOne());
} catch (NoSuchMethodException nsme) {
try {
integrator = clz.getConstructor(Field.class,

5
src/test/java/org/apache/commons/math4/ode/nonstiff/ClassicalRungKuttaFieldStepInterpolatorTest.java
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@ -41,4 +41,9 @@ public class ClassicalRungKuttaFieldStepInterpolatorTest extends AbstractRungeKu
doInterpolationInside(Decimal64Field.getInstance(), 2.6e-7, 3.6e-6);
}
@Test
public void nonFieldInterpolatorConsistency() {
doNonFieldInterpolatorConsistency(Decimal64Field.getInstance(), 2.8e-17, 1.2e-16, 2.3e-16, 1.0e-50);
}
}

5
src/test/java/org/apache/commons/math4/ode/nonstiff/EulerFieldStepInterpolatorTest.java
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@ -41,4 +41,9 @@ public class EulerFieldStepInterpolatorTest extends AbstractRungeKuttaFieldStepI
doInterpolationInside(Decimal64Field.getInstance(), 3.3e-4, 7.9e-3);
}
@Test
public void nonFieldInterpolatorConsistency() {
doNonFieldInterpolatorConsistency(Decimal64Field.getInstance(), 1.0e-50, 1.0e-50, 1.0e-50, 1.0e-50);
}
}

5
src/test/java/org/apache/commons/math4/ode/nonstiff/GillFieldStepInterpolatorTest.java
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@ -41,4 +41,9 @@ public class GillFieldStepInterpolatorTest extends AbstractRungeKuttaFieldStepIn
doInterpolationInside(Decimal64Field.getInstance(), 2.6e-7, 3.6e-6);
}
@Test
public void nonFieldInterpolatorConsistency() {
doNonFieldInterpolatorConsistency(Decimal64Field.getInstance(), 1.4e-17, 1.0e-50, 1.0e-50, 1.0e-50);
}
}

5
src/test/java/org/apache/commons/math4/ode/nonstiff/LutherFieldStepInterpolatorTest.java
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@ -41,4 +41,9 @@ public class LutherFieldStepInterpolatorTest extends AbstractRungeKuttaFieldStep
doInterpolationInside(Decimal64Field.getInstance(), 1.1e-7, 9.6e-9);
}
@Test
public void nonFieldInterpolatorConsistency() {
doNonFieldInterpolatorConsistency(Decimal64Field.getInstance(), 8.4e-17, 2.3e-16, 2.1e-14, 1.3e-15);
}
}

5
src/test/java/org/apache/commons/math4/ode/nonstiff/MidpointFieldStepInterpolatorTest.java
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@ -41,4 +41,9 @@ public class MidpointFieldStepInterpolatorTest extends AbstractRungeKuttaFieldSt
doInterpolationInside(Decimal64Field.getInstance(), 3.3e-4, 1.1e-5);
}
@Test
public void nonFieldInterpolatorConsistency() {
doNonFieldInterpolatorConsistency(Decimal64Field.getInstance(), 1.0e-50, 1.0e-50, 1.0e-50, 1.0e-50);
}
}

5
src/test/java/org/apache/commons/math4/ode/nonstiff/ThreeEighthesFieldStepInterpolatorTest.java
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@ -41,4 +41,9 @@ public class ThreeEighthesFieldStepInterpolatorTest extends AbstractRungeKuttaFi
doInterpolationInside(Decimal64Field.getInstance(), 2.6e-7, 3.6e-6);
}
@Test
public void nonFieldInterpolatorConsistency() {
doNonFieldInterpolatorConsistency(Decimal64Field.getInstance(), 1.4e-17, 1.2e-16, 1.0e-50, 1.0e-50);
}
}