ptolemy.actor.lib
Class IIR

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.actor.lib.IIR

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 IIR
extends Transformer

This actor is an implementation of an infinite impulse response IIR filter. A direct form II [1] implementation is used. This actor is type polymorphic. Its input, output, numerator and denominator types can be any type of Token supporting the basic arithmetic operations (add, subtract and multiply).

This filter has a transfer function given by: References

[1]A. V. Oppenheim, R. W. Schafer, Discrete-Time Signal Processing, Prentice Hall, 1989.

Since:

Ptolemy II 1.0

Version:

$Id: IIR.java 58234 2010-06-17 00:26:52Z cxh $

Author:

Brian K. Vogel, Steve Neuendorffer, Aleksandar Necakov, Research in Motion Limited

See Also:

Serialized Form

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (vogel)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

private int	_currentTap
private Token[]	_denominator
private Token	_latestWindow
private Token[]	_numerator
private Token[]	_stateVector
Parameter	denominator This parameter represents the denominator coefficients as an array of a tokens.
Parameter	numerator This parameter represents the numerator coefficients as an array of tokens.

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

IIR(CompositeEntity container, java.lang.String name)
Construct an actor with the given container and name.

Method Summary

private Token	_computeOutput(Token xCurrent)
private void	_initStateVector()
void	attributeChanged(Attribute attribute) Handle parameter change events on the numerator and denominator parameters.
java.lang.Object	clone(Workspace workspace) Clone the actor into the specified workspace.
void	fire() If at least one input token is available, consume a single input token, apply the filter to that input token, and compute a single output token.
void	initialize() Initialize the filter state vector with zero state.
boolean	postfire() Update the filter state.

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, preinitialize, 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, preinitialize, 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

numerator

public Parameter numerator

This parameter represents the numerator coefficients as an array of tokens. The format is {b₀, b₁, ..., b_M}. The default value of this parameter is {1.0}.

denominator

public Parameter denominator

This parameter represents the denominator coefficients as an array of a tokens. The format is {a₀, a₁, ..., a_N}. Note that the value of a₀ is constrained to be 1.0. This implementation will issue a warning if it is not. The default value of this parameter is {1.0}.

_numerator

private Token[] _numerator

_denominator

private Token[] _denominator

_stateVector

private Token[] _stateVector

_currentTap

private int _currentTap

_latestWindow

private Token _latestWindow

Constructor Detail

IIR

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

Construct an actor with the given container and name.

Parameters:

container - The container.

name - The name of this actor.

Throws:

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

NameDuplicationException - If the container already has an actor with this name.

Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

Handle parameter change events on the numerator and denominator parameters. The filter state vector is reinitialized to zero state.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that changed.

Throws:

IllegalActionException - If this method is invoked with an unrecognized parameter.

clone

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

Clone the actor into the specified workspace. This calls the base class and then sets the type constraints.

Overrides:

clone in class AtomicActor

Parameters:

workspace - The workspace for the new object.

Returns:

A new actor.

Throws:

java.lang.CloneNotSupportedException - If a derived class has an attribute that cannot be cloned.

See Also:

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

fire

public void fire()
          throws IllegalActionException

If at least one input token is available, consume a single input token, apply the filter to that input token, and compute a single output token. If this method is invoked multiple times in one iteration, then only the input read on the last invocation in the iteration will affect the filter state.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - Not thrown in this base class.

initialize

public void initialize()
                throws IllegalActionException

Initialize the filter state vector with zero state.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If the base class throws it.

postfire

public boolean postfire()
                 throws IllegalActionException

Update the filter state.

Specified by:

postfire in interface Executable

Overrides:

postfire in class AtomicActor

Returns:

True if execution can continue into the next iteration.

Throws:

IllegalActionException - If the base class throws it.

_computeOutput

private Token _computeOutput(Token xCurrent)
                      throws IllegalActionException

Throws:

IllegalActionException

_initStateVector

private void _initStateVector()
                       throws IllegalActionException

Throws:

IllegalActionException