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.domains.sdf.lib.Chop
- All Implemented Interfaces:
- java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, SequenceActor, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable
public class Chop
- extends SDFTransformer
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:
- Proposed Rating:
Fields inherited from class ptolemy.kernel.util.NamedObj |
_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS |
Constructor Summary |
Chop(CompositeEntity container,
java.lang.String name)
Construct an actor in the specified container with the specified
name. |
Method Summary |
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.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.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 |
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
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.
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.