Class Neuron
java.lang.Object
org.apache.commons.math3.ml.neuralnet.Neuron
- All Implemented Interfaces:
Serializable
Describes a neuron element of a neural network.
This class aims to be thread-safe.
- Since:
- 3.3
- See Also:
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Nested Class Summary
Nested Classes -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final AtomicReference
<double[]> Neuron data.private final long
Identifier.private final AtomicLong
Number of attempts to update a neuron.private final AtomicLong
Number of successful updates of a neuron.private static final long
Serializable.private final int
Length of the feature set. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
compareAndSetFeatures
(double[] expect, double[] update) Tries to atomically update the neuron's features.private boolean
containSameValues
(double[] current, double[] expect) Checks whether the contents of both arrays is the same.copy()
Performs a deep copy of this instance.double[]
Gets the neuron's features.long
Gets the neuron's identifier.long
Retrieves the number of calls to thecompareAndSetFeatures
method.long
Retrieves the number of successful calls to thecompareAndSetFeatures
method.int
getSize()
Gets the length of the feature set.private void
Prevents proxy bypass.private Object
Custom serialization.
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Field Details
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serialVersionUID
private static final long serialVersionUIDSerializable.- See Also:
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identifier
private final long identifierIdentifier. -
size
private final int sizeLength of the feature set. -
features
Neuron data. -
numberOfAttemptedUpdates
Number of attempts to update a neuron. -
numberOfSuccessfulUpdates
Number of successful updates of a neuron.
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Constructor Details
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Neuron
Neuron(long identifier, double[] features) Creates a neuron. The size of the feature set is fixed to the length of the given argument.
Constructor is package-private: Neurons must becreated
by the network instance to which they will belong.- Parameters:
identifier
- Identifier (assigned by theNetwork
).features
- Initial values of the feature set.
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Method Details
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copy
Performs a deep copy of this instance. Upon return, the copied and original instances will be independent: Updating one will not affect the other.- Returns:
- a new instance with the same state as this instance.
- Since:
- 3.6
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getIdentifier
public long getIdentifier()Gets the neuron's identifier.- Returns:
- the identifier.
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getSize
public int getSize()Gets the length of the feature set.- Returns:
- the number of features.
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getFeatures
public double[] getFeatures()Gets the neuron's features.- Returns:
- a copy of the neuron's features.
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compareAndSetFeatures
public boolean compareAndSetFeatures(double[] expect, double[] update) Tries to atomically update the neuron's features. Update will be performed only if the expected values match the current values.
In effect, when concurrent threads call this method, the state could be modified by one, so that it does not correspond to the the state assumed by another. Typically, a callerretrieves the current state
, and uses it to compute the new state. During this computation, another thread might have done the same thing, and updated the state: If the current thread were to proceed with its own update, it would overwrite the new state (which might already have been used by yet other threads). To prevent this, the method does not perform the update when a concurrent modification has been detected, and returnsfalse
. When this happens, the caller should fetch the new current state, redo its computation, and call this method again.- Parameters:
expect
- Current values of the features, as assumed by the caller. Update will never succeed if the contents of this array does not match the values returned bygetFeatures()
.update
- Features's new values.- Returns:
true
if the update was successful,false
otherwise.- Throws:
DimensionMismatchException
- if the length ofupdate
is not the same as specified in theconstructor
.
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getNumberOfAttemptedUpdates
public long getNumberOfAttemptedUpdates()Retrieves the number of calls to thecompareAndSetFeatures
method. Note that if the caller wants to use this method in combination withgetNumberOfSuccessfulUpdates()
, additional synchronization may be required to ensure consistency.- Returns:
- the number of update attempts.
- Since:
- 3.6
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getNumberOfSuccessfulUpdates
public long getNumberOfSuccessfulUpdates()Retrieves the number of successful calls to thecompareAndSetFeatures
method. Note that if the caller wants to use this method in combination withgetNumberOfAttemptedUpdates()
, additional synchronization may be required to ensure consistency.- Returns:
- the number of successful updates.
- Since:
- 3.6
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containSameValues
private boolean containSameValues(double[] current, double[] expect) Checks whether the contents of both arrays is the same.- Parameters:
current
- Current values.expect
- Expected values.- Returns:
true
if the arrays contain the same values.- Throws:
DimensionMismatchException
- if the length ofexpected
is not the same as specified in theconstructor
.
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readObject
Prevents proxy bypass.- Parameters:
in
- Input stream.
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writeReplace
Custom serialization.- Returns:
- the proxy instance that will be actually serialized.
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