ptolemy.domains.ct.kernel.solver
Class DerivativeResolver

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.domains.ct.kernel.ODESolver
          ptolemy.domains.ct.kernel.solver.DerivativeResolver

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, BreakpointODESolver, Changeable, Debuggable, DebugListener, Derivable, ModelErrorHandler, MoMLExportable, Moveable, Nameable

public class DerivativeResolver
extends ODESolver
implements BreakpointODESolver

This solver finds the derivatives of the state variables of an ODE with respect to the current time. For example, if the ODE is

 x' = f(x, u, t),
 

the current time is t0, and

 x(t0) = x0,
 

then this method calculates

 x'(t0) = f(x(t0), u(t0), t0).
 

The derivative is obtained by firing the system for one iteration. This is used for preparing the history for other methods. Note that time does not progress under this solver. So, this class implements BreakpointODESolver and can only be used as a breakpoint solver.

Since:

Ptolemy II 0.4

Version:

$Id: DerivativeResolver.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Jie Liu, Haiyang Zheng

See Also:

Serialized Form

Accepted Rating:

Green (hyzheng)

Proposed Rating:

Green (hyzheng)

Nested Class Summary

Nested classes/interfaces inherited from class ptolemy.kernel.util.NamedObj

NamedObj.ContainedObjectsIterator

Field Summary

private static java.lang.String

_DEFAULT_NAME Name of this Solver.

Fields inherited from class ptolemy.kernel.util.NamedObj

_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS

Constructor Summary

DerivativeResolver()
Construct a solver in the default workspace with the name "CT_Derivative_Resolver".

DerivativeResolver(Workspace workspace)
Construct a solver in the given workspace with the name "CT_Derivative_Resolver".

Method Summary

void	fireStateTransitionActors() Fire state transition actors, set converged flag to true indicating a fixed-point states have been reached.
int	getAmountOfHistoryInformation() Return 0 to indicate that no history information is needed by this solver.
int	getIntegratorAuxVariableCount() Return 0 to indicate that the solver needs no auxiliary variable.
void	integratorFire(CTBaseIntegrator integrator) Fire the given integrator.
boolean	integratorIsAccurate(CTBaseIntegrator integrator) Return true, since there is no step size control.
double	integratorPredictedStepSize(CTBaseIntegrator integrator) Return the initial step size of the director.

Methods inherited from class ptolemy.domains.ct.kernel.ODESolver

_advanceModelTime, _getRoundCount, _getSchedule, _incrementRoundCount, _isConverged, _makeSolverOf, _resetRoundCount, _setConverged, _voteForConverged, fireDynamicActors, getContainer, resolveStates

Methods inherited from class ptolemy.kernel.util.NamedObj

_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _description, _exportMoMLContents, _getContainedObject, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateExistence, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, _validateSettables, addChangeListener, addDebugListener, attributeChanged, attributeList, attributeList, attributeTypeChanged, clone, clone, containedObjectsIterator, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getElementName, getFullName, getModelErrorHandler, getName, getName, getPrototypeList, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setName, setPersistent, setSource, sortContainedObjects, toplevel, toString, uniqueName, validateSettables, workspace

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

_DEFAULT_NAME

private static final java.lang.String _DEFAULT_NAME

Name of this Solver.

See Also:

Constant Field Values

Constructor Detail

DerivativeResolver

public DerivativeResolver()

Construct a solver in the default workspace with the name "CT_Derivative_Resolver". The solver is added to the list of objects in the workspace. Increment the version number of the workspace.

DerivativeResolver

public DerivativeResolver(Workspace workspace)

Construct a solver in the given workspace with the name "CT_Derivative_Resolver". If the workspace argument is null, use the default workspace. The solver is added to the list of objects in the workspace. Increment the version number of the workspace.

Parameters:

workspace - Object for synchronization and version tracking

Method Detail

fireStateTransitionActors

public void fireStateTransitionActors()
                               throws IllegalActionException

Fire state transition actors, set converged flag to true indicating a fixed-point states have been reached.

Overrides:

fireStateTransitionActors in class ODESolver

Throws:

IllegalActionException - If thrown in the super class.

getAmountOfHistoryInformation

public final int getAmountOfHistoryInformation()

Return 0 to indicate that no history information is needed by this solver.

Specified by:

getAmountOfHistoryInformation in class ODESolver

Returns:

0.

getIntegratorAuxVariableCount

public final int getIntegratorAuxVariableCount()

Return 0 to indicate that the solver needs no auxiliary variable.

Specified by:

getIntegratorAuxVariableCount in class ODESolver

Returns:

0.

integratorFire

public void integratorFire(CTBaseIntegrator integrator)
                    throws IllegalActionException

Fire the given integrator. Build history information by recording the current input as the derivative and using the old state as the tentative state. Note that this method is called during the discrete phase of execution of an integration. See the _propagateResolvedStates() and _discretePhaseExecution() methods in CTMultiSolverDirector class.

Specified by:

integratorFire in class ODESolver

Parameters:

integrator - The integrator of that calls this method.

Throws:

IllegalActionException - If can not read input.

integratorIsAccurate

public boolean integratorIsAccurate(CTBaseIntegrator integrator)

Return true, since there is no step size control.

Specified by:

integratorIsAccurate in class ODESolver

Parameters:

integrator - The integrator of that calls this method.

Returns:

True always.

integratorPredictedStepSize

public double integratorPredictedStepSize(CTBaseIntegrator integrator)

Return the initial step size of the director. Since this solver is always used as the breakpoint solver, the next integration step will use the initial step size.

Specified by:

integratorPredictedStepSize in class ODESolver

Parameters:

integrator - The integrator of that calls this method.

Returns:

The initial step size.