ptolemy.domains.ct.lib
Class CTPeriodicSampler

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.actor.lib.Transformer
                              ptolemy.domains.ct.lib.CTPeriodicSampler

All Implemented Interfaces:

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

public class CTPeriodicSampler
extends Transformer
implements CTEventGenerator

This actor generates discrete events by periodically sampling a CT signal. The events have the values of the input signal at the sampling times. The sampling rate is given by parameter "samplePeriod", which has default value 0.1. The actor has a multi-input port and a multi-output port. Signals in each input channel are sampled and produced to corresponding output channel.

Since:

Ptolemy II 0.3

Version:

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

Author:

Jie Liu, Haiyang Zheng

See Also:

Serialized Form

Accepted Rating:

Red (cxh)

Proposed Rating:

Yellow (hyzheng)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

private boolean	_hasCurrentEvent
private Time	_nextSamplingTime
private double	_samplePeriod
Parameter	samplePeriod The parameter for the sampling period.

Fields inherited from class ptolemy.actor.lib.Transformer

input, output

Fields inherited from class ptolemy.actor.AtomicActor

_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested

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

CTPeriodicSampler(CompositeEntity container, java.lang.String name)
Construct an actor in the specified container with the specified name.

Method Summary

void	attributeChanged(Attribute attribute) Update the local cache of the sampling period if it has been changed.
java.lang.Object	clone(Workspace workspace) Clone this actor into the specified workspace.
void	fire() Generate a discrete event if the current time is one of the sampling times.
boolean	hasCurrentEvent() Return true if there is a current event.
void	initialize() Set the next sampling time as the start time (i.e. the current time).
boolean	postfire() Set the next sampling time and return true.
void	preinitialize() Make sure the actor runs inside a CT domain.

Methods inherited from class ptolemy.actor.TypedAtomicActor

_addPort, _fireAt, _fireAt, attributeTypeChanged, clone, newPort, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.AtomicActor

_actorFiring, _actorFiring, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, prefire, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup

Methods inherited from class ptolemy.kernel.ComponentEntity

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

Methods inherited from class ptolemy.kernel.Entity

_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName

Methods inherited from class ptolemy.kernel.InstantiableNamedObj

_setParent, exportMoML, 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, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeList, attributeList, 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, requestChange, 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, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList

Methods inherited from interface ptolemy.actor.Executable

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

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, removeInitializable, wrapup

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

samplePeriod

public Parameter samplePeriod

The parameter for the sampling period. It contains a double token whose default value is 0.1.

_hasCurrentEvent

private boolean _hasCurrentEvent

_nextSamplingTime

private Time _nextSamplingTime

_samplePeriod

private double _samplePeriod

Constructor Detail

CTPeriodicSampler

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

Construct an actor in the specified container with the specified name. The name must be unique within the container or an exception is thrown. The container argument must not be null, or a NullPointerException will be thrown. The actor can be either dynamic, or not. It must be set at the construction time and can't be changed thereafter. A dynamic actor will produce a token at its initialization phase.

Parameters:

container - The container of this actor.

name - The actor's name

Throws:

IllegalActionException - If the entity cannot be contained by the proposed container.

NameDuplicationException - If name coincides with an entity already in the container.

Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

Update the local cache of the sampling period if it has been changed.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that changed.

Throws:

IllegalActionException - If the sampling period is less than or equal to 0.

clone

public java.lang.Object clone(Workspace workspace)
                       throws java.lang.CloneNotSupportedException

Clone this actor into the specified workspace. The new actor is not added to the directory of that workspace (you must do this yourself if you want it there). The result is a new actor with the same ports as the original, but no connections and no container. A container must be set before much can be done with this actor.

Overrides:

clone in class AtomicActor

Parameters:

workspace - The workspace for the cloned object.

Returns:

A new ComponentEntity.

Throws:

java.lang.CloneNotSupportedException - If cloned ports cannot have as their container the cloned entity (this should not occur), or if one of the attributes cannot be cloned.

See Also:

NamedObj.exportMoML(Writer, int, String), NamedObj.setDeferringChangeRequests(boolean)

fire

public void fire()
          throws IllegalActionException

Generate a discrete event if the current time is one of the sampling times. The value of the event is the value of the input signal at the current time.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If the transfer of tokens failed.

hasCurrentEvent

public boolean hasCurrentEvent()

Return true if there is a current event. In other words, the current time is one of the sampling times.

Specified by:

hasCurrentEvent in interface CTEventGenerator

Returns:

If there is a discrete event to emit.

initialize

public void initialize()
                throws IllegalActionException

Set the next sampling time as the start time (i.e. the current time). We do not register the start time as a breakpoint, since the director will fire at the start time any way.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If thrown by the supper class.

postfire

public boolean postfire()
                 throws IllegalActionException

Set the next sampling time and return true. It computes the next sampling time, and registers it as a breakpoint.

Specified by:

postfire in interface Executable

Overrides:

postfire in class AtomicActor

Returns:

True.

Throws:

IllegalActionException - If the next sampling time can not be set as a breakpoint.

preinitialize

public void preinitialize()
                   throws IllegalActionException

Make sure the actor runs inside a CT domain.

Specified by:

preinitialize in interface Initializable

Overrides:

preinitialize in class AtomicActor

Throws:

IllegalActionException - If the director is not a CTDirector or the parent class throws it.