ptolemy.domains.sdf.lib
Class Autocorrelation
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.Autocorrelation
- 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 Autocorrelation
- extends SDFTransformer
This actor calculates the autocorrelation of a sequence of input tokens.
It is polymorphic, supporting any input data type that supports
multiplication, addition, and division by an integer.
However, since integer division will lose the fractional portion of the
result, type resolution will resolve the input type to double or double
matrix if the input port is connected to an integer or integer matrix source,
respectively.
Both biased and unbiased autocorrelation estimates are supported.
If the parameter biased is true, then
the autocorrelation estimate is
N-1-k
1 ---
r(k) = - \ x(n)x(n+k)
N /
---
n=0
for k = 0, ... , p, where N is the number of
inputs to average (numberOfInputs), p is the number of
lags to estimate (numberOfLags), and x* is the
conjugate of the input (if it is complex).
This estimate is biased because the outermost lags have fewer than N
terms in the summation, and yet the summation is still normalized by N.
If the parameter biased is false (the default), then the estimate is
N-1-k
1 ---
r(k) = --- \ x(n)x(n+k)
N-k /
---
n=0
In this case, the estimate is unbiased.
However, note that the unbiased estimate does not guarantee
a positive definite sequence, so a power spectral estimate based on this
autocorrelation estimate may have negative components.
The output will be an array of tokens whose type is at least that
of the input. If the parameter symmetricOutput is true,
then the output will be symmetric and have length equal to twice
the number of lags requested plus one. Otherwise, the output
will have length equal to twice the number of lags requested,
which will be almost symmetric (insert the last
sample into the first position to get the symmetric output that you
would get with the symmetricOutput being true).
- Since:
- Ptolemy II 1.0
- Version:
- $Id: Autocorrelation.java 59167 2010-09-21 17:08:02Z cxh $
- Author:
- Edward A. Lee and Yuhong Xiong
- 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 |
|
Method Summary |
void |
attributeChanged(Attribute attribute)
Check to see that the numberOfInputs parameter is positive,
and that the numberOfLags parameter is positive. |
java.lang.Object |
clone(Workspace workspace)
Clone the actor into the specified workspace. |
void |
fire()
Consume tokens from the input and produce a token on the output
that contains an array token that represents an autocorrelation
estimate of the consumed tokens. |
boolean |
prefire()
If there are not sufficient inputs, then return false. |
| Methods inherited from class ptolemy.actor.AtomicActor |
_actorFiring, _actorFiring, addActorFiringListener, addInitializable, 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.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 |
biased
public Parameter biased
- If true, the estimate will be biased.
This is a boolean with default value false.
numberOfInputs
public Parameter numberOfInputs
- Number of input samples to average.
This is an integer with default value 256.
numberOfLags
public Parameter numberOfLags
- Number of autocorrelation lags to output.
This is an integer with default value 64.
symmetricOutput
public Parameter symmetricOutput
- If true, then the output from each firing
will have 2*numberOfLags + 1
samples (an odd number) whose values are symmetric about
the midpoint. If false, then the output from each firing will
have 2*numberOfLags samples (an even number)
by omitting one of the endpoints (the last one).
This is a boolean with default value false.
_numberOfInputs
private int _numberOfInputs
_numberOfLags
private int _numberOfLags
_lengthOfOutput
private int _lengthOfOutput
_symmetricOutput
private boolean _symmetricOutput
_outputs
private Token[] _outputs
Autocorrelation
public Autocorrelation(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.
attributeChanged
public void attributeChanged(Attribute attribute)
throws IllegalActionException
- Check to see that the numberOfInputs parameter is positive,
and that the numberOfLags parameter is positive. Based on the
new values, recompute the size of the output array.
- Overrides:
attributeChanged in class NamedObj
- Parameters:
attribute - The attribute that has changed.
- Throws:
IllegalActionException - If the parameters are out of range.
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
- Consume tokens from the input and produce a token on the output
that contains an array token that represents an autocorrelation
estimate of the consumed tokens. The estimate is consistent with
the parameters of the object, as described in the class comment.
- Specified by:
fire in interface Executable- Overrides:
fire in class AtomicActor
- Throws:
IllegalActionException - If there is no director.
prefire
public boolean prefire()
throws IllegalActionException
- If there are not sufficient inputs, then return false.
Otherwise, return whatever the base class returns.
- Specified by:
prefire in interface Executable- Overrides:
prefire in class SDFTransformer
- Returns:
- True if it is ok to continue.
- Throws:
IllegalActionException - If the base class throws it.