ptolemy.domains.continuous.lib
Class ContinuousTransferFunction

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.kernel.CompositeEntity
                      ptolemy.actor.CompositeActor
                          ptolemy.actor.TypedCompositeActor
                              ptolemy.domains.continuous.lib.ContinuousTransferFunction

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable

public class ContinuousTransferFunction
extends TypedCompositeActor

A transfer function in the continuous time domain. This actor implements a transfer function where the single input (u) and single output (y) can be expressed in (Laplace) transfer function form as the following equation:

 y(s)    b(1)*s^(m-1) + b(2)*s^(m-2) + ... + b(m)
 ----- = -------------------------------------------
 u(s)    a(1)*s^(n-1) + a(2)*s^(n-2) + ... + a(n)
 

where m and n are the number of numerator and denominator coefficients, respectively. This actors has two parameters -- numerator and denominator -- containing the coefficients of the numerator and denominator in descending powers of s. These coefficients are double numbers. The order of the denominator (n) must be greater than or equal to the order of the numerator (m).

This actor extends TypedCompositeActor and works as a higher-order function. Whenever the parameters are changed, the actor will build a transparent subsystem inside it using integrators, adders, and scales. This is called a realization of the transfer function. Notice that there are infinite number of realizations of a transfer function, and they are equivalent if and only if the initial conditions are all zero. Here we choose the controllable canonical form and preset all initial states of the integrators to zero. If you need to set arbitrary initial conditions you have to use the state-space representation, for example, use the LinearStateSpace actor.

Since:

Ptolemy II 8.0

Version:

$Id: ContinuousTransferFunction.java 57046 2010-01-27 23:35:53Z cxh $

Author:

Christopher Brooks, based on the CT ContinuousTransferFunction by Jie Liu

See Also:

Serialized Form

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (liuj)

Nested Class Summary

Nested classes/interfaces inherited from class ptolemy.kernel.CompositeEntity

CompositeEntity.ContainedObjectsIterator

Field Summary

private boolean	_opaque Opaqueness.
Parameter	denominator The coefficients of the denominator, containing an array of DoubleTokens.
TypedIOPort	input Single input port.
Parameter	numerator The coefficients of the numerator, containing an array of DoubleTokens.
TypedIOPort	output Single output port.

Fields inherited from class ptolemy.actor.CompositeActor

_actorFiringListeners, _causalityInterface, _initializables, _notifyingActorFiring, _publishedPorts, _publisherRelations, _stopRequested

Fields inherited from class ptolemy.kernel.CompositeEntity

_levelCrossingLinks

Fields inherited from class ptolemy.kernel.util.NamedObj

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

Fields inherited from interface ptolemy.actor.Executable

COMPLETED, NOT_READY, STOP_ITERATING

Constructor Summary

ContinuousTransferFunction(CompositeEntity container, java.lang.String name)
Construct the composite actor with a name and a container.

ContinuousTransferFunction(Workspace workspace)
Construct a ContinuousTransferFunction in the specified workspace with no container and an empty string as a name.

Method Summary

private void	_init() Initialize the class.
void	attributeChanged(Attribute attribute) If the argument is the numerator or the denominator parameters, request for initialization from the director if there is one.
Director	getDirector() Return the executive director, regardless what isOpaque returns.
boolean	isOpaque() Return the opaqueness of this composite actor.
void	preinitialize() Sanity check the parameters; if the parameters are legal create a continuous-time subsystem that implement the transfer function, preinitialize all the actors in the subsystem, and set the opaqueness of this actor to true.
void	wrapup() Set the opaqueness to true and wrapup.

Methods inherited from class ptolemy.actor.TypedCompositeActor

_addEntity, _addPort, _addRelation, _checkTypesFromTo, _typeConstraintsFromTo, newPort, newRelation, resolveTypes, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.CompositeActor

_actorFiring, _actorFiring, _finishedAddEntity, _getPublishedPort, _setDirector, addActorFiringListener, addInitializable, addPiggyback, clone, connectionsChanged, createReceivers, createSchedule, fire, getCausalityInterface, getExecutiveDirector, getManager, inferringWidths, inferWidths, initialize, inputPortList, isFireFunctional, isStrict, iterate, linkToPublishedPort, linkToPublishedPort, needsWidthInference, newInsideReceiver, newReceiver, notifyConnectivityChange, outputPortList, postfire, prefire, recordFiring, registerPublisherPort, removeActorFiringListener, removeInitializable, removePiggyback, requestChange, setContainer, setDirector, setManager, stop, stopFire, terminate, unlinkToPublishedPort, unlinkToPublishedPort, unregisterPublisherPort

Methods inherited from class ptolemy.kernel.CompositeEntity

_adjustDeferrals, _deepOpaqueEntityList, _description, _exportMoMLContents, _recordDecoratedAttributes, _removeEntity, _removeRelation, _validateSettables, allAtomicEntityList, allCompositeEntityList, allowLevelCrossingConnect, classDefinitionList, connect, connect, containedObjectsIterator, deepEntityList, deepGetEntities, deepOpaqueEntityList, deepRelationSet, entityList, entityList, exportLinks, exportMoML, getAttribute, getEntities, getEntity, getPort, getRelation, getRelations, isAtomic, lazyAllAtomicEntityList, lazyAllCompositeEntityList, lazyClassDefinitionList, lazyDeepEntityList, lazyEntityList, lazyRelationList, numberOfEntities, numberOfRelations, numEntities, numRelations, relationList, removeAllEntities, removeAllRelations, setClassDefinition, statistics, uniqueName

Methods inherited from class ptolemy.kernel.ComponentEntity

_checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName

Methods inherited from class ptolemy.kernel.Entity

_removePort, connectedPortList, connectedPorts, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts

Methods inherited from class ptolemy.kernel.InstantiableNamedObj

_setParent, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition

Methods inherited from class ptolemy.kernel.util.NamedObj

_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeList, attributeList, attributeTypeChanged, clone, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace

Methods inherited from class java.lang.Object

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

Methods inherited from interface ptolemy.actor.Actor

createReceivers, getCausalityInterface, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList

Methods inherited from interface ptolemy.actor.Executable

fire, isFireFunctional, isStrict, iterate, postfire, prefire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, initialize, removeInitializable

Methods inherited from interface ptolemy.kernel.util.Nameable

description, getContainer, getDisplayName, getFullName, getName, getName, setName

Methods inherited from interface ptolemy.kernel.util.Derivable

getDerivedLevel, getDerivedList, propagateValue

Field Detail

input

public TypedIOPort input

Single input port.

output

public TypedIOPort output

Single output port.

numerator

public Parameter numerator

The coefficients of the numerator, containing an array of DoubleTokens. The default value is {1.0}.

denominator

public Parameter denominator

The coefficients of the denominator, containing an array of DoubleTokens. The array must have a length greater than or equal to the length of the numerator. The default value is {1.0}.

_opaque

private boolean _opaque

Opaqueness.

Constructor Detail

ContinuousTransferFunction

public ContinuousTransferFunction(CompositeEntity container,
                                  java.lang.String name)
                           throws NameDuplicationException,
                                  IllegalActionException

Construct the composite actor with a name and a container.

Parameters:

container - The container.

name - The name.

Throws:

NameDuplicationException - If another entity already had this name.

IllegalActionException - If there was an internal problem.

ContinuousTransferFunction

public ContinuousTransferFunction(Workspace workspace)
                           throws IllegalActionException,
                                  NameDuplicationException

Construct a ContinuousTransferFunction in the specified workspace with no container and an empty string as a name. You can then change the name with setName(). If the workspace argument is null, then use the default workspace.

Parameters:

workspace - The workspace that will list the actor.

Throws:

IllegalActionException - If the name has a period in it, or the director is not compatible with the specified container.

NameDuplicationException - If the container already contains an entity with the specified name.

Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

If the argument is the numerator or the denominator parameters, request for initialization from the director if there is one. Also check that the denominator vector cannot start with 0. Other sanity checks, like that the denominator must have a higher order than that of the numerator, and that the first element of the denominator should not be zero, are done in the preinitialize() method.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that changed.

Throws:

IllegalActionException - If the numerator and the denominator matrix is not a row vector.

getDirector

public Director getDirector()

Return the executive director, regardless what isOpaque returns.

Specified by:

getDirector in interface Actor

Overrides:

getDirector in class CompositeActor

Returns:

The director responsible for invocation of inside actors.

See Also:

CompositeActor.setDirector(Director)

isOpaque

public boolean isOpaque()

Return the opaqueness of this composite actor. This actor is opaque if it has not been preinitialized after creation or changes of parameters. Otherwise, it is not opaque.

Overrides:

isOpaque in class CompositeActor

Returns:

True if the entity is opaque.

See Also:

CompositeEntity

preinitialize

public void preinitialize()
                   throws IllegalActionException

Sanity check the parameters; if the parameters are legal create a continuous-time subsystem that implement the transfer function, preinitialize all the actors in the subsystem, and set the opaqueness of this actor to true. This method need the write access on the workspace.

Specified by:

preinitialize in interface Initializable

Overrides:

preinitialize in class CompositeActor

Throws:

IllegalActionException - If there is no ContinuousDirector, or any contained actors throw it in its preinitialize() method .

wrapup

public void wrapup()
            throws IllegalActionException

Set the opaqueness to true and wrapup.

Specified by:

wrapup in interface Initializable

Overrides:

wrapup in class CompositeActor

Throws:

IllegalActionException - If there is no director.

_init

private void _init()
            throws IllegalActionException,
                   NameDuplicationException

Initialize the class.

Throws:

IllegalActionException

NameDuplicationException