ptolemy.actor.lib.logic
Class Comparator

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.logic.Comparator

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 Comparator
extends TypedAtomicActor

Compare two double-valued inputs, and output the boolean result of the comparison. The exact comparison performed is given by the comparison attribute, which can take any of the following values:

• >: left > right
• >=: left >= right
• <: left < right
• <=: left <= right
• ==: left == right

The default is ">". The input ports are named left and right to indicate which side of the comparison operator their value appears on.

The tolerance parameter, which defaults to zero, defines an error tolerance. That is, the actor may produce true even if the specified test is not exactly satisfied, but rather is almost satisfied, within the specified tolerance.

Note that this actor will work with any data type that can be losslessly converted to doubles, such as integers.

Since:

Ptolemy II 1.0

Version:

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

Author:

Edward A. Lee

See Also:

Serialized Form

Accepted Rating:

Green (neuendor)

Proposed Rating:

Green (eal)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

private int	_comparison
private static int	_EQ
private static int	_GE
private static int	_GT
private static int	_LE
private static int	_LT
private double	_tolerance
StringAttribute	comparison The comparison operator.
TypedIOPort	left The left input port, which has type double.
TypedIOPort	output The output port, which has type boolean.
TypedIOPort	right The right input port, which has type double.
Parameter	tolerance The tolerance for the comparison.

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

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

Method Summary

void	attributeChanged(Attribute attribute) Override the base class to determine which comparison is being specified.
void	fire() Consume exactly one input token from each input port, and compute the specified comparison.
boolean	prefire() Check that each input port has at least one token, and if so, return the result of the superclass prefire() method.

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, clone, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, initialize, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, postfire, 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, postfire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, initialize, 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

left

public TypedIOPort left

The left input port, which has type double.

right

public TypedIOPort right

The right input port, which has type double.

output

public TypedIOPort output

The output port, which has type boolean.

comparison

public StringAttribute comparison

The comparison operator. This is a string-valued attribute that defaults to ">".

tolerance

public Parameter tolerance

The tolerance for the comparison. This has type double, and defaults to 0.0.

_comparison

private int _comparison

_tolerance

private double _tolerance

_LT

private static final int _LT

See Also:

Constant Field Values

_LE

private static final int _LE

See Also:

Constant Field Values

_GT

private static final int _GT

See Also:

Constant Field Values

_GE

private static final int _GE

See Also:

Constant Field Values

_EQ

private static final int _EQ

See Also:

Constant Field Values

Constructor Detail

Comparator

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

Construct an actor with the given container and name. Set the comparison to the default (">"). Set the types of the input ports to double, and the type of the output port to boolean.

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

Override the base class to determine which comparison is being specified. Read the value of the comparison attribute and set the cached value appropriately.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that changed.

Throws:

IllegalActionException - If the comparison is not recognized.

fire

public void fire()
          throws IllegalActionException

Consume exactly one input token from each input port, and compute the specified comparison. This method assumes that both ports have an input, as checked by prefire().

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If there is no director.

prefire

public boolean prefire()
                throws IllegalActionException

Check that each input port has at least one token, and if so, return the result of the superclass prefire() method. Otherwise, return false.

Specified by:

prefire in interface Executable

Overrides:

prefire in class AtomicActor

Returns:

True if there inputs available on both input ports.

Throws:

IllegalActionException - If the base class throws it.