ai.djl.nn.core

Class Prelu

java.lang.Object

ai.djl.nn.AbstractBlock

ai.djl.nn.ParameterBlock

ai.djl.nn.core.Prelu

All Implemented Interfaces:

Block

public class Prelu
extends ParameterBlock

Applies Leaky Parametric ReLU activation element-wise to the input.

Leaky ReLUs attempt to fix the 'dying ReLU' problem by allowing a small slope when the input is negative and has a slope of one when input is positive. This is defined by \(y= x \gt 0 ? x : slope * x\).

Parametric ReLU is a Leaky ReLU in which the slope is learnt during training.

Field Summary

Fields inherited from class ai.djl.nn.AbstractBlock

inputNames, inputShapes

Constructor Summary

Constructors

Constructor and Description
Prelu() Creates a Parametric ReLU Block.

Method Summary

Modifier and Type	Method and Description
NDList	forward(ParameterStore parameterStore, NDList inputs, ai.djl.util.PairList<java.lang.String,java.lang.Object> params) Applies the operating function of the block once.
java.util.List<Parameter>	getDirectParameters() Returns a list of all the direct parameters of the block.
Shape[]	getOutputShapes(NDManager manager, Shape[] inputs) Returns the expected output shapes of the block for the specified input shapes.
Shape	getParameterShape(java.lang.String name, Shape[] inputShapes) Returns the shape of the specified direct parameter of this block given the shapes of the input to the block.
void	loadParameters(NDManager manager, java.io.DataInputStream is) Loads the parameters from the given input stream.
void	saveParameters(java.io.DataOutputStream os) Writes the parameters of the block to the given outputStream.

Methods inherited from class ai.djl.nn.ParameterBlock

getChildren, initialize, toString

Methods inherited from class ai.djl.nn.AbstractBlock

beforeInitialize, cast, clear, describeInput, getParameters, isInitialized, setInitializer, setInitializer

Methods inherited from class java.lang.Object

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

Methods inherited from interface ai.djl.nn.Block

forward, validateLayout

Constructor Detail

Prelu

public Prelu()

Creates a Parametric ReLU Block.

Method Detail

forward

public NDList forward(ParameterStore parameterStore,
                      NDList inputs,
                      ai.djl.util.PairList<java.lang.String,java.lang.Object> params)

Applies the operating function of the block once. This method should be called only on blocks that are initialized.

Parameters:

parameterStore - the parameter store

inputs - the input NDList

params - optional parameters

Returns:

the output of the forward pass

getOutputShapes

public Shape[] getOutputShapes(NDManager manager,
                               Shape[] inputs)

Returns the expected output shapes of the block for the specified input shapes.

Parameters:

manager - an NDManager

inputs - the shapes of the inputs

Returns:

the expected output shapes of the block

getDirectParameters

public java.util.List<Parameter> getDirectParameters()

Returns a list of all the direct parameters of the block.

Returns:

the list of Parameter

getParameterShape

public Shape getParameterShape(java.lang.String name,
                               Shape[] inputShapes)

Returns the shape of the specified direct parameter of this block given the shapes of the input to the block.

Parameters:

name - the name of the parameter

inputShapes - the shapes of the input to the block

Returns:

the shape of the parameter specified

saveParameters

public void saveParameters(java.io.DataOutputStream os)
                    throws java.io.IOException

Writes the parameters of the block to the given outputStream.

Parameters:

os - the outputstream to save the parameters to

Throws:

java.io.IOException - if an I/O error occurs

loadParameters

public void loadParameters(NDManager manager,
                           java.io.DataInputStream is)
                    throws java.io.IOException,
                           MalformedModelException

Loads the parameters from the given input stream.

Parameters:

manager - an NDManager to create the parameter arrays

is - the inputstream that stream the parameter values

Throws:

java.io.IOException - if an I/O error occurs

MalformedModelException - if the model file is corrupted or unsupported