org.deeplearning4j.nn.conf.layers.recurrent

Class LastTimeStep

java.lang.Object

org.deeplearning4j.nn.conf.layers.Layer

org.deeplearning4j.nn.conf.layers.wrapper.BaseWrapperLayer

org.deeplearning4j.nn.conf.layers.recurrent.LastTimeStep

All Implemented Interfaces:

Serializable, Cloneable, TrainingConfig

public class LastTimeStep
extends BaseWrapperLayer

LastTimeStep is a "wrapper" layer: it wraps any RNN layer, and extracts out the last time step during forward pass, and returns it as a row vector (per example). That is, for 3d (time series) input (with shape [minibatch, layerSize, timeSeriesLength]), we take the last time step and return it as a 2d array with shape [minibatch, layerSize].
Note that the last time step operation takes into account any mask arrays, if present: thus, variable length time series (in the same minibatch) are handled as expected here.

Author:

Alex Black

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.deeplearning4j.nn.conf.layers.Layer

Layer.Builder<T extends Layer.Builder<T>>

Field Summary

Fields inherited from class org.deeplearning4j.nn.conf.layers.wrapper.BaseWrapperLayer

underlying

Fields inherited from class org.deeplearning4j.nn.conf.layers.Layer

constraints, iDropout, layerName

Constructor Summary

Constructors

Constructor and Description
LastTimeStep(Layer underlying)

Method Summary

Modifier and Type	Method and Description
InputType	getOutputType(int layerIndex, InputType inputType) For a given type of input to this layer, what is the type of the output?
Layer	getUnderlying()
Layer	instantiate(NeuralNetConfiguration conf, Collection<TrainingListener> trainingListeners, int layerIndex, INDArray layerParamsView, boolean initializeParams)

Methods inherited from class org.deeplearning4j.nn.conf.layers.wrapper.BaseWrapperLayer

getGradientNormalization, getGradientNormalizationThreshold, getL1ByParam, getL2ByParam, getMemoryReport, getPreProcessorForInputType, initializer, isPretrain, isPretrainParam, setLayerName, setNIn

Methods inherited from class org.deeplearning4j.nn.conf.layers.Layer

clone, getUpdaterByParam, initializeConstraints, resetLayerDefaultConfig, setPretrain

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.deeplearning4j.nn.api.TrainingConfig

getLayerName

Constructor Detail

LastTimeStep

public LastTimeStep(Layer underlying)

Method Detail

getUnderlying

public Layer getUnderlying()

instantiate

public Layer instantiate(NeuralNetConfiguration conf,
                         Collection<TrainingListener> trainingListeners,
                         int layerIndex,
                         INDArray layerParamsView,
                         boolean initializeParams)

Specified by:

instantiate in class Layer

getOutputType

public InputType getOutputType(int layerIndex,
                               InputType inputType)

Description copied from class: Layer

For a given type of input to this layer, what is the type of the output?

Overrides:

getOutputType in class BaseWrapperLayer

Parameters:

layerIndex - Index of the layer

inputType - Type of input for the layer

Returns:

Type of output from the layer