Package ai.djl.nn

Class LambdaBlock

java.lang.Object

ai.djl.nn.AbstractBaseBlock

ai.djl.nn.AbstractBlock

ai.djl.nn.LambdaBlock

All Implemented Interfaces:

Block

public class LambdaBlock
extends AbstractBlock

LambdaBlock is a Block with no parameters or children.

LambdaBlock allows converting any function that takes an NDList as input and returns an NDList into a parameter-less and child-less Block. This can be useful in converting activation functions, identity blocks, and more. For example, identity block can be created as new LambdaBlock(x -> x).

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_NAME

Fields inherited from class ai.djl.nn.AbstractBlock

children, parameters

Fields inherited from class ai.djl.nn.AbstractBaseBlock

inputNames, inputShapes, outputDataTypes, version

Constructor Summary

Constructors

Constructor	Description
LambdaBlock(Function<NDList,NDList> lambda)	Creates a LambdaBlock that can apply the specified function.
LambdaBlock(Function<NDList,NDList> lambda, String name)	Creates a LambdaBlock that can apply the specified function.

Method Summary

Modifier and Type	Method	Description
protected NDList	forwardInternal(ParameterStore parameterStore, NDList inputs, boolean training, ai.djl.util.PairList<String,Object> params)	A helper for Block.forward(ParameterStore, NDList, boolean, PairList) after initialization.
String	getName()	Returns the lambda function name.
Shape[]	getOutputShapes(Shape[] inputShapes)	Returns the expected output shapes of the block for the specified input shapes.
void	loadParameters(NDManager manager, DataInputStream is)	Loads the parameters from the given input stream.
static LambdaBlock	singleton(Function<NDArray,NDArray> lambda)	Creates a LambdaBlock for a singleton function.
static LambdaBlock	singleton(Function<NDArray,NDArray> lambda, String name)	Creates a LambdaBlock for a singleton function.

Methods inherited from class ai.djl.nn.AbstractBlock

addChildBlock, addChildBlock, addChildBlockSingleton, addParameter, getChildren, getDirectParameters

Methods inherited from class ai.djl.nn.AbstractBaseBlock

beforeInitialize, cast, clear, describeInput, forward, forward, forwardInternal, getInputShapes, getOutputDataTypes, getParameters, initialize, initializeChildBlocks, isInitialized, loadMetadata, prepare, readInputShapes, saveInputShapes, saveMetadata, saveParameters, setInitializer, setInitializer, setInitializer, toString

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, freezeParameters, freezeParameters, getCustomMetadata, getOutputShapes

Field Details

DEFAULT_NAME

public static final String DEFAULT_NAME

See Also:

• Constant Field Values

Constructor Details

LambdaBlock

public LambdaBlock(Function<NDList,NDList> lambda)

Creates a LambdaBlock that can apply the specified function.

Parameters:

lambda - the function to apply

LambdaBlock

public LambdaBlock(Function<NDList,NDList> lambda,
 String name)

Creates a LambdaBlock that can apply the specified function.

Parameters:

lambda - the function to apply

name - the function name

Method Details

getName

public String getName()

Returns the lambda function name.

Returns:

the lambda function name

singleton

public static LambdaBlock singleton(Function<NDArray,NDArray> lambda)

Creates a LambdaBlock for a singleton function.

Parameters:

lambda - a function accepting a singleton NDList and returning another singleton NDList

Returns:

a new LambdaBlock for the function

singleton

public static LambdaBlock singleton(Function<NDArray,NDArray> lambda,
 String name)

Creates a LambdaBlock for a singleton function.

Parameters:

lambda - a function accepting a singleton NDList and returning another singleton NDList

name - the function name

Returns:

a new LambdaBlock for the function

forwardInternal

protected NDList forwardInternal(ParameterStore parameterStore,
 NDList inputs,
 boolean training,
 ai.djl.util.PairList<String,Object> params)

A helper for Block.forward(ParameterStore, NDList, boolean, PairList) after initialization.

Specified by:

forwardInternal in class AbstractBaseBlock

Parameters:

parameterStore - the parameter store

inputs - the input NDList

training - true for a training forward pass

params - optional parameters

Returns:

the output of the forward pass

getOutputShapes

public Shape[] getOutputShapes(Shape[] inputShapes)

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

Parameters:

inputShapes - the shapes of the inputs

Returns:

the expected output shapes of the block

loadParameters

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

Loads the parameters from the given input stream.

Specified by:

loadParameters in interface Block

Overrides:

loadParameters in class AbstractBaseBlock

Parameters:

manager - an NDManager to create the parameter arrays

is - the inputstream that stream the parameter values

Throws:

IOException - if an I/O error occurs

MalformedModelException - if the model file is corrupted or unsupported