Element-wise non-linear activation (Identity, Sigmoid, Tanh, ReLU, Softmax). More...

#include <operators.h>

Inheritance diagram for opennn::ActivationOp:

Public Types
enum class	Function { Identity , Sigmoid , Tanh , ReLU , Softmax }
	Supported activation functions. More...

Public Member Functions
void	set_function (Function new_function)
	Selects the activation function and configures cuDNN descriptors.

void	set_function (const string &name)
	Selects the activation function by name (delegates to set_function(Function)).

void	forward_propagate (ForwardPropagation &fp, size_t layer, bool is_training) noexcept override
	Runs the operator's forward computation.

void	back_propagate (ForwardPropagation &fp, BackPropagation &bp, size_t layer) const noexcept override
	Runs the operator's backward computation, accumulating into gradient/delta buffers.

void	apply_cpu (TensorView &output)
	CPU forward implementation; applies the activation in place on `output`.

void	apply_gpu (TensorView &output)
	GPU forward implementation; applies the activation in place on `output`.

void	apply_delta (const TensorView &outputs, TensorView &delta) const
	Multiplies `delta` by the derivative of the activation evaluated at `outputs`.

void	to_JSON (JsonWriter &w) const override
	Serializes the operator configuration to a JSON writer.

void	from_JSON (const Json *parent) override
	Restores the operator configuration from a JSON node.

void	destroy_cuda () override
	Releases CUDA resources owned by the operator; called from destructors.

	~ActivationOp () override

	ActivationOp ()=default

	ActivationOp (const ActivationOp &)=delete

ActivationOp &	operator= (const ActivationOp &)=delete

Public Member Functions inherited from opennn::Operator
virtual	~Operator ()=default

virtual vector< TensorSpec >	parameter_specs () const
	Returns the tensor specs of trainable parameters owned by this operator.

virtual vector< TensorSpec >	state_specs () const
	Returns the tensor specs of persistent state owned by this operator.

virtual void	link_parameters (span< const TensorView >)
	Binds parameter views provided by the hosting layer.

virtual void	link_gradients (span< const TensorView >)
	Binds gradient views provided by the hosting layer.

virtual void	link_states (span< const TensorView >)
	Binds state views provided by the hosting layer.

virtual void	set_parameters_random ()
	Initializes parameters with random values.

virtual void	set_parameters_glorot ()
	Initializes parameters using Glorot (Xavier) initialization.

virtual void	load_state_from_JSON (const Json *)
	Restores persistent state (e.g. running statistics) from a JSON node.

TensorView &	get_input (ForwardPropagation &fp, size_t layer, size_t i=0) const noexcept

vector< TensorView > &	get_inputs (ForwardPropagation &fp, size_t layer, size_t i=0) const noexcept

TensorView &	get_output (ForwardPropagation &fp, size_t layer, size_t i=0) const noexcept

TensorView &	get_output_delta (BackPropagation &bp, size_t layer, size_t i=0) const noexcept

TensorView &	get_input_delta (BackPropagation &bp, size_t layer, size_t i=0) const noexcept

Static Public Member Functions
static const EnumMap< Function > &	map ()
	Returns the bidirectional mapping between Function values and their string names.

static Function	from_string (const string &name)
	Returns the Function corresponding to a string name.

static const string &	to_string (Function function)
	Returns the string name of a Function.

static cudnnActivationMode_t	to_cudnn_mode (Function function)
	Returns the cuDNN activation mode corresponding to a Function.

Public Attributes
Function	function = Function::Identity

cudnnActivationDescriptor_t	descriptor = nullptr

vector< size_t >	output_slots_backward

Public Attributes inherited from opennn::Operator
vector< size_t >	input_slots = {0}

vector< size_t >	output_slots = {1}

vector< size_t >	input_delta_slots = {1}

vector< size_t >	output_delta_slots = {0}

Detailed Description

Element-wise non-linear activation (Identity, Sigmoid, Tanh, ReLU, Softmax).

Member Enumeration Documentation

◆ Function

enum class opennn::ActivationOp::Function

strong

Supported activation functions.

Enumerator
Identity
Sigmoid
Tanh
ReLU
Softmax

Constructor & Destructor Documentation

◆ ~ActivationOp()

opennn::ActivationOp::~ActivationOp ( )

inlineoverride

◆ ActivationOp() [1/2]

opennn::ActivationOp::ActivationOp ( )

default

◆ ActivationOp() [2/2]

opennn::ActivationOp::ActivationOp ( const ActivationOp & )

delete

Member Function Documentation

◆ apply_cpu()

void opennn::ActivationOp::apply_cpu ( TensorView & output )

CPU forward implementation; applies the activation in place on output.

◆ apply_delta()

void opennn::ActivationOp::apply_delta	(	const TensorView &	outputs,
		TensorView &	delta ) const

Multiplies delta by the derivative of the activation evaluated at outputs.

◆ apply_gpu()

void opennn::ActivationOp::apply_gpu ( TensorView & output )

GPU forward implementation; applies the activation in place on output.

◆ back_propagate()

void opennn::ActivationOp::back_propagate	(	ForwardPropagation &	fp,
		BackPropagation &	bp,
		size_t	layer ) const

overridevirtualnoexcept

Runs the operator's backward computation, accumulating into gradient/delta buffers.

Parameters

fp	Forward propagation workspace (read-only).
bp	Back propagation workspace receiving gradients and deltas.
layer	Index of the hosting layer in the workspace.

Reimplemented from opennn::Operator.

◆ destroy_cuda()

void opennn::ActivationOp::destroy_cuda ( )

overridevirtual

Releases CUDA resources owned by the operator; called from destructors.

Reimplemented from opennn::Operator.

◆ forward_propagate()

void opennn::ActivationOp::forward_propagate	(	ForwardPropagation &	fp,
		size_t	layer,
		bool	is_training )

overridevirtualnoexcept

Runs the operator's forward computation.

Parameters

fp	Forward propagation workspace.
layer	Index of the hosting layer in the workspace.
is_training	If true, enables training-only behavior (e.g. dropout sampling).

Reimplemented from opennn::Operator.

◆ from_JSON()

void opennn::ActivationOp::from_JSON ( const Json * )

overridevirtual

Restores the operator configuration from a JSON node.

Reimplemented from opennn::Operator.

◆ from_string()

static Function opennn::ActivationOp::from_string ( const string & name )

static

Returns the Function corresponding to a string name.

◆ map()

static const EnumMap< Function > & opennn::ActivationOp::map ( )

static

Returns the bidirectional mapping between Function values and their string names.

◆ operator=()

ActivationOp & opennn::ActivationOp::operator= ( const ActivationOp & )

delete

◆ set_function() [1/2]

void opennn::ActivationOp::set_function ( const string & name )

Selects the activation function by name (delegates to set_function(Function)).

◆ set_function() [2/2]

void opennn::ActivationOp::set_function ( Function new_function )

Selects the activation function and configures cuDNN descriptors.

◆ to_cudnn_mode()

static cudnnActivationMode_t opennn::ActivationOp::to_cudnn_mode ( Function function )

static

Returns the cuDNN activation mode corresponding to a Function.

◆ to_JSON()

void opennn::ActivationOp::to_JSON ( JsonWriter & ) const

overridevirtual

Serializes the operator configuration to a JSON writer.

Reimplemented from opennn::Operator.

◆ to_string()

static const string & opennn::ActivationOp::to_string ( Function function )

static

Returns the string name of a Function.

Member Data Documentation

◆ descriptor

cudnnActivationDescriptor_t opennn::ActivationOp::descriptor = nullptr

◆ function

Function opennn::ActivationOp::function = Function::Identity

◆ output_slots_backward

vector<size_t> opennn::ActivationOp::output_slots_backward

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Enumeration Documentation

◆ Function

Constructor & Destructor Documentation

◆ ~ActivationOp()

◆ ActivationOp() [1/2]

◆ ActivationOp() [2/2]

Member Function Documentation

◆ apply_cpu()

◆ apply_delta()

◆ apply_gpu()

◆ back_propagate()

◆ destroy_cuda()

◆ forward_propagate()

◆ from_JSON()

◆ from_string()

◆ map()

◆ operator=()

◆ set_function() [1/2]

◆ set_function() [2/2]

◆ to_cudnn_mode()

◆ to_JSON()

◆ to_string()

Member Data Documentation

◆ descriptor

◆ function

◆ output_slots_backward