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Simplified integration end handling using the same method as other integrators 

(based on a dedicated event handler)

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/branches/MATH_2_0@675589 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Luc Maisonobe 2008-07-10 14:22:13 +00:00
parent df6766e1e3
commit b51a782d1b
1 changed files with 15 additions and 20 deletions
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35
src/java/org/apache/commons/math/ode/nonstiff/EmbeddedRungeKuttaIntegrator.java
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@ -20,6 +20,7 @@ package org.apache.commons.math.ode.nonstiff;
import org.apache.commons.math.ode.DerivativeException; import org.apache.commons.math.ode.DerivativeException;
import org.apache.commons.math.ode.FirstOrderDifferentialEquations; import org.apache.commons.math.ode.FirstOrderDifferentialEquations;
import org.apache.commons.math.ode.IntegratorException; import org.apache.commons.math.ode.IntegratorException;
import org.apache.commons.math.ode.events.CombinedEventsManager;
import org.apache.commons.math.ode.sampling.AbstractStepInterpolator; import org.apache.commons.math.ode.sampling.AbstractStepInterpolator;
import org.apache.commons.math.ode.sampling.DummyStepInterpolator; import org.apache.commons.math.ode.sampling.DummyStepInterpolator;
import org.apache.commons.math.ode.sampling.StepHandler; import org.apache.commons.math.ode.sampling.StepHandler;
@ -190,14 +191,18 @@ public abstract class EmbeddedRungeKuttaIntegrator
} }
interpolator.storeTime(t0); interpolator.storeTime(t0);
stepStart = t0; // set up integration control objects
stepStart = t0;
double hNew = 0; double hNew = 0;
boolean firstTime = true; boolean firstTime = true;
boolean lastStep;
for (StepHandler handler : stepHandlers) { for (StepHandler handler : stepHandlers) {
handler.reset(); handler.reset();
} }
do { CombinedEventsManager manager = addEndTimeChecker(t, eventsHandlersManager);
boolean lastStep = false;
// main integration loop
while (!lastStep) {
interpolator.shift(); interpolator.shift();
@ -226,12 +231,6 @@ public abstract class EmbeddedRungeKuttaIntegrator
stepSize = hNew; stepSize = hNew;
// step adjustment near bounds
if ((forward && (stepStart + stepSize > t)) ||
((! forward) && (stepStart + stepSize < t))) {
stepSize = t - stepStart;
}
// next stages // next stages
for (int k = 1; k < stages; ++k) { for (int k = 1; k < stages; ++k) {
@ -260,11 +259,11 @@ public abstract class EmbeddedRungeKuttaIntegrator
error = estimateError(yDotK, y, yTmp, stepSize); error = estimateError(yDotK, y, yTmp, stepSize);
if (error <= 1.0) { if (error <= 1.0) {
// Discrete events handling // discrete events handling
interpolator.storeTime(stepStart + stepSize); interpolator.storeTime(stepStart + stepSize);
if (eventsHandlersManager.evaluateStep(interpolator)) { if (manager.evaluateStep(interpolator)) {
// reject the step to match exactly the next switch time // reject the step to match exactly the next switch time
hNew = eventsHandlersManager.getEventTime() - stepStart; hNew = manager.getEventTime() - stepStart;
} else { } else {
// accept the step // accept the step
loop = false; loop = false;
@ -283,12 +282,8 @@ public abstract class EmbeddedRungeKuttaIntegrator
// the step has been accepted // the step has been accepted
final double nextStep = stepStart + stepSize; final double nextStep = stepStart + stepSize;
System.arraycopy(yTmp, 0, y, 0, y0.length); System.arraycopy(yTmp, 0, y, 0, y0.length);
eventsHandlersManager.stepAccepted(nextStep, y); manager.stepAccepted(nextStep, y);
if (eventsHandlersManager.stop()) { lastStep = manager.stop();
lastStep = true;
} else {
lastStep = forward ? (nextStep >= t) : (nextStep <= t);
}
// provide the step data to the step handler // provide the step data to the step handler
interpolator.storeTime(nextStep); interpolator.storeTime(nextStep);
@ -302,7 +297,7 @@ public abstract class EmbeddedRungeKuttaIntegrator
System.arraycopy(yDotK[stages - 1], 0, yDotK[0], 0, y0.length); System.arraycopy(yDotK[stages - 1], 0, yDotK[0], 0, y0.length);
} }
if (eventsHandlersManager.reset(stepStart, y) && ! lastStep) { if (manager.reset(stepStart, y) && ! lastStep) {
// some event handler has triggered changes that // some event handler has triggered changes that
// invalidate the derivatives, we need to recompute them // invalidate the derivatives, we need to recompute them
equations.computeDerivatives(stepStart, y, yDotK[0]); equations.computeDerivatives(stepStart, y, yDotK[0]);
@ -319,7 +314,7 @@ public abstract class EmbeddedRungeKuttaIntegrator
hNew = filterStep(scaledH, nextIsLast); hNew = filterStep(scaledH, nextIsLast);
} }
} while (! lastStep); }
final double stopTime = stepStart; final double stopTime = stepStart;
resetInternalState(); resetInternalState();