ptolemy.backtrack.automatic.ptolemy.domains.sdf.lib
Class Chop

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.domains.sdf.lib.SDFTransformer
                              ptolemy.backtrack.automatic.ptolemy.domains.sdf.lib.Chop

All Implemented Interfaces:

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

public class Chop
extends SDFTransformer
implements Rollbackable

This actor reads a sequence of input tokens of any type, and writes a sequence of tokens constructed from the input sequence (possibly supplemented with zeros). The number of input tokens consumed is given by numberToRead, and the number of output tokens produced is given by numberToWrite. The offset parameter (default 0) specifies where in the output block the first (oldest) input that is read should go. If offset is positive and usePastInputs is true, then the first few outputs will come from values read in previous iterations.

A simple use of this actor is to pad a block of inputs with zeros. Set offset to zero and use numberToWrite > numberToRead.

Another simple use is to obtain overlapping windows from an input stream. Set usePastInputs to true, use numberToWrite > numberToRead, and set offset equal to numberToWrite - numberToRead.

The general operation is illustrated with the following examples. If offset is positive, there two possible scenarios, illustrated by the following examples:

 iiiiii                  numberToRead = 6
 \    \                 offset = 2
 ppiiiiii00              numberToWrite = 10
 iiiiii                  numberToRead = 6
 \ \  \                 offset = 2
 ppiii                   numberToWrite = 5
 

The symbol "i" refers to any input token. The leftmost symbol refers to the oldest input token of the ones consumed in a given firing. The symbol "p" refers to a token that is either zero (if usePastInputs is false) or is equal to a previously consumed input token (if usePastInputs is true). The symbol "0" refers to a zero-valued token. In the first of the above examples, the entire input block is copied to the output, and then filled out with zeros. In the second example, only a portion of the input block fits. The remaining input tokens are discarded, although they might be used in subsequent firings if usePastInputs is true.

When the offset is negative, this indicates that the first offset input tokens that are read should be discarded. The corresponding scenarios are shown below:

 iiiiii                  numberToRead = 6
 / /  /                   offset = -2
 iiii000000              numberToWrite = 10
 iiiiii                  numberToRead = 6
 / / //                   offset = -2
 iii                     numberToWrite = 3
 

In the first of these examples, the first two input tokens are discarded. In the second example, the first two and the last input token are discarded.

The zero-valued tokens are constructed using the zero() method of the first input token that is read in the firing. This returns a zero-valued token with the same type as the input.

Since:

Ptolemy II 1.0

Version:

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

Author:

Edward A. Lee

See Also:

Serialized Form

Accepted Rating:

Yellow (neuendor)

Proposed Rating:

Green (eal)

Nested Class Summary

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

Entity.ContainedObjectsIterator

Field Summary

private Token[]	_buffer
private int	_highLimit
private int	_inputIndex
private int	_lowLimit
private int	_numberToRead
private int	_numberToWrite
private int	_offsetValue
private Token[]	_pastBuffer
private boolean	_pastNeedsInitializing
private boolean	_usePast
protected Checkpoint	$CHECKPOINT
private FieldRecord	$RECORD$_buffer
private FieldRecord	$RECORD$_highLimit
private FieldRecord	$RECORD$_inputIndex
private FieldRecord	$RECORD$_lowLimit
private FieldRecord	$RECORD$_numberToRead
private FieldRecord	$RECORD$_numberToWrite
private FieldRecord	$RECORD$_offsetValue
private FieldRecord	$RECORD$_pastBuffer
private FieldRecord	$RECORD$_pastNeedsInitializing
private FieldRecord	$RECORD$_usePast
protected CheckpointRecord	$RECORD$$CHECKPOINT
private FieldRecord[]	$RECORDS
Parameter	numberToRead The number of input tokens to read.
Parameter	numberToWrite The number of tokens to write to the output.
Parameter	offset Start of output block relative to start of input block.
Parameter	usePastInputs If offset is greater than 0, specify whether to use previously read inputs (otherwise use zeros).

Fields inherited from class ptolemy.domains.sdf.lib.SDFTransformer

input, input_tokenConsumptionRate, output, output_tokenInitProduction, output_tokenProductionRate

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

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

Method Summary

private Token	$ASSIGN$_buffer(int index0, Token newValue)
private Token[]	$ASSIGN$_buffer(Token[] newValue)
private int	$ASSIGN$_highLimit(int newValue)
private int	$ASSIGN$_inputIndex(int newValue)
private int	$ASSIGN$_lowLimit(int newValue)
private int	$ASSIGN$_numberToRead(int newValue)
private int	$ASSIGN$_numberToWrite(int newValue)
private int	$ASSIGN$_offsetValue(int newValue)
private Token	$ASSIGN$_pastBuffer(int index0, Token newValue)
private Token[]	$ASSIGN$_pastBuffer(Token[] newValue)
private boolean	$ASSIGN$_pastNeedsInitializing(boolean newValue)
private boolean	$ASSIGN$_usePast(boolean newValue)
private Token[]	$BACKUP$_buffer()
private Token[]	$BACKUP$_pastBuffer()
void	$COMMIT(long timestamp) Commit changes up to the given timestamp, but not including changes made at timestamp and afterward.
Checkpoint	$GET$CHECKPOINT() Get the checkpoint object that monitors this rollbackable object.
void	$RESTORE(long timestamp, boolean trim) Restore a previous state to all the private fields of this rollbackable object.
java.lang.Object	$SET$CHECKPOINT(Checkpoint checkpoint) Set the checkpoint object of this rollbackable object.
void	attributeChanged(Attribute attribute) Check the validity of parameter values and using the new values, recompute the size of the internal buffers.
void	fire() Consume the specified number of input tokens, and produce the specified number of output tokens.
void	initialize() Override the base class to ensure that the past buffer gets initialized.

Methods inherited from class ptolemy.domains.sdf.lib.SDFTransformer

prefire

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, 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, 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

$CHECKPOINT

protected transient Checkpoint $CHECKPOINT

numberToRead

public Parameter numberToRead

The number of input tokens to read. This is an integer, with default 128.

numberToWrite

public Parameter numberToWrite

The number of tokens to write to the output. This is an integer, with default 64.

offset

public Parameter offset

Start of output block relative to start of input block. This is an integer, with default 0.

usePastInputs

public Parameter usePastInputs

If offset is greater than 0, specify whether to use previously read inputs (otherwise use zeros). This is a boolean, with default true.

_highLimit

private int _highLimit

_inputIndex

private int _inputIndex

_lowLimit

private int _lowLimit

_numberToRead

private int _numberToRead

_numberToWrite

private int _numberToWrite

_offsetValue

private int _offsetValue

_buffer

private Token[] _buffer

_pastBuffer

private Token[] _pastBuffer

_usePast

private boolean _usePast

_pastNeedsInitializing

private boolean _pastNeedsInitializing

$RECORD$$CHECKPOINT

protected transient CheckpointRecord $RECORD$$CHECKPOINT

$RECORD$_highLimit

private transient FieldRecord $RECORD$_highLimit

$RECORD$_inputIndex

private transient FieldRecord $RECORD$_inputIndex

$RECORD$_lowLimit

private transient FieldRecord $RECORD$_lowLimit

$RECORD$_numberToRead

private transient FieldRecord $RECORD$_numberToRead

$RECORD$_numberToWrite

private transient FieldRecord $RECORD$_numberToWrite

$RECORD$_offsetValue

private transient FieldRecord $RECORD$_offsetValue

$RECORD$_buffer

private transient FieldRecord $RECORD$_buffer

$RECORD$_pastBuffer

private transient FieldRecord $RECORD$_pastBuffer

$RECORD$_usePast

private transient FieldRecord $RECORD$_usePast

$RECORD$_pastNeedsInitializing

private transient FieldRecord $RECORD$_pastNeedsInitializing

$RECORDS

private transient FieldRecord[] $RECORDS

Constructor Detail

Chop

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

Construct an actor in the specified container with the specified name.

Parameters:

container - The container.

name - The name.

Throws:

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

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

Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

Check the validity of parameter values and using the new values, recompute the size of the internal buffers.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that has changed.

Throws:

IllegalActionException - If the parameters are out of range.

fire

public void fire()
          throws IllegalActionException

Consume the specified number of input tokens, and produce the specified number of output tokens.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If there is no director.

initialize

public void initialize()
                throws IllegalActionException

Override the base class to ensure that the past buffer gets initialized.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If the superclass throws it.

$ASSIGN$_highLimit

private final int $ASSIGN$_highLimit(int newValue)

$ASSIGN$_inputIndex

private final int $ASSIGN$_inputIndex(int newValue)

$ASSIGN$_lowLimit

private final int $ASSIGN$_lowLimit(int newValue)

$ASSIGN$_numberToRead

private final int $ASSIGN$_numberToRead(int newValue)

$ASSIGN$_numberToWrite

private final int $ASSIGN$_numberToWrite(int newValue)

$ASSIGN$_offsetValue

private final int $ASSIGN$_offsetValue(int newValue)

$ASSIGN$_buffer

private final Token[] $ASSIGN$_buffer(Token[] newValue)

$ASSIGN$_buffer

private final Token $ASSIGN$_buffer(int index0,
                                    Token newValue)

$BACKUP$_buffer

private final Token[] $BACKUP$_buffer()

$ASSIGN$_pastBuffer

private final Token[] $ASSIGN$_pastBuffer(Token[] newValue)

$ASSIGN$_pastBuffer

private final Token $ASSIGN$_pastBuffer(int index0,
                                        Token newValue)

$BACKUP$_pastBuffer

private final Token[] $BACKUP$_pastBuffer()

$ASSIGN$_usePast

private final boolean $ASSIGN$_usePast(boolean newValue)

$ASSIGN$_pastNeedsInitializing

private final boolean $ASSIGN$_pastNeedsInitializing(boolean newValue)

$COMMIT

public void $COMMIT(long timestamp)

Description copied from interface: Rollbackable

Commit changes up to the given timestamp, but not including changes made at timestamp and afterward.

Specified by:

$COMMIT in interface Rollbackable

Parameters:

timestamp - The timestamp.

$RESTORE

public void $RESTORE(long timestamp,
                     boolean trim)

Description copied from interface: Rollbackable

Restore a previous state to all the private fields of this rollbackable object.

Specified by:

$RESTORE in interface Rollbackable

Parameters:

timestamp - The timestamp taken at the time when the previous state was recorded.

trim - Whether to delete the records used for the rollback.

See Also:

Checkpoint.rollback(long, boolean)

$GET$CHECKPOINT

public final Checkpoint $GET$CHECKPOINT()

Description copied from interface: Rollbackable

Get the checkpoint object that monitors this rollbackable object.

Specified by:

$GET$CHECKPOINT in interface Rollbackable

Returns:

The checkpoint object.

$SET$CHECKPOINT

public final java.lang.Object $SET$CHECKPOINT(Checkpoint checkpoint)

Description copied from interface: Rollbackable

Set the checkpoint object of this rollbackable object. A merge operation is performed on the current checkpoint object and the new checkpoint object, so that the two checkpoint objects monitor the same set of objects when this function returns.

Specified by:

$SET$CHECKPOINT in interface Rollbackable

Parameters:

checkpoint - The new checkpoint object.

Returns:

This rollbackable object itself.

See Also:

Checkpoint.setCheckpoint(Checkpoint)