A Gather layer in a network definition. Supports several kinds of gathering. More...

#include <NvInfer.h>

Inheritance diagram for nvinfer1::IGatherLayer:

Public Member Functions
void	setGatherAxis (int32_t axis) noexcept
	Set the axis used by GatherMode::kELEMENTS and GatherMode::kDEFAULT The axis must be less than the number of dimensions in the data input. The axis defaults to 0. More...

int32_t	getGatherAxis () const noexcept
	Get the axis to gather on. More...

void	setNbElementWiseDims (int32_t elementWiseDims) noexcept
	Set the number of leading dimensions of indices tensor to be handled elementwise. The gathering of indexing starts from the dimension of data[NbElementWiseDims:]. The NbElementWiseDims must be less than the Rank of the data input. More...

int32_t	getNbElementWiseDims () const noexcept
	Get the number of leading dimensions of indices tensor to be handled elementwise. More...

void	setMode (GatherMode mode) noexcept
	Set the gather mode. More...

GatherMode	getMode () const noexcept
	Get the gather mode. More...

Public Member Functions inherited from nvinfer1::ILayer
LayerType	getType () const noexcept
	Return the type of a layer. More...

void	setName (char const *name) noexcept
	Set the name of a layer. More...

char const *	getName () const noexcept
	Return the name of a layer. More...

int32_t	getNbInputs () const noexcept
	Get the number of inputs of a layer. More...

ITensor *	getInput (int32_t index) const noexcept
	Get the layer input corresponding to the given index. More...

int32_t	getNbOutputs () const noexcept
	Get the number of outputs of a layer. More...

ITensor *	getOutput (int32_t index) const noexcept
	Get the layer output corresponding to the given index. More...

void	setInput (int32_t index, ITensor &tensor) noexcept
	Replace an input of this layer with a specific tensor. More...

void	setPrecision (DataType dataType) noexcept
	Set the computational precision of this layer. More...

DataType	getPrecision () const noexcept
	get the computational precision of this layer More...

bool	precisionIsSet () const noexcept
	whether the computational precision has been set for this layer More...

void	resetPrecision () noexcept
	reset the computational precision for this layer More...

void	setOutputType (int32_t index, DataType dataType) noexcept
	Set the output type of this layer. More...

DataType	getOutputType (int32_t index) const noexcept
	get the output type of this layer More...

bool	outputTypeIsSet (int32_t index) const noexcept
	whether the output type has been set for this layer More...

void	resetOutputType (int32_t index) noexcept
	reset the output type for this layer More...

Protected Member Functions
virtual	~IGatherLayer () noexcept=default

Protected Member Functions inherited from nvinfer1::ILayer
virtual	~ILayer () noexcept=default

Protected Member Functions inherited from nvinfer1::INoCopy
	INoCopy ()=default

virtual	~INoCopy ()=default

	INoCopy (INoCopy const &other)=delete

INoCopy &	operator= (INoCopy const &other)=delete

	INoCopy (INoCopy &&other)=delete

INoCopy &	operator= (INoCopy &&other)=delete

Protected Attributes
apiv::VGatherLayer *	mImpl

Protected Attributes inherited from nvinfer1::ILayer
apiv::VLayer *	mLayer

Detailed Description

A Gather layer in a network definition. Supports several kinds of gathering.

The Gather layer has two input tensors, Data and Indices, and an output tensor Output. Additionally, there are three parameters: mode, nbElementwiseDims, and axis that control how the indices are interpreted.

Data is a tensor of rank r >= 1 that stores the values to be gathered in Output.
Indices is a tensor of rank q that determines which locations in Data to gather.
- GatherMode::kDEFAULT: q >= 0
- GatherMode::kND: q >= 1 and the last dimension of Indices must be a build time constant.
- GatherMode::kELEMENT: q = r
Output stores the gathered results. Its rank s depends on the mode:
- GatherMode::kDEFAULT: s = q + r - 1 - nbElementwiseDims
- GatherMode::kND: s = q + r - indices.d[q-1] - 1 - nbElementwiseDims
- GatherMode::kELEMENT: s = q = r. The output can be a shape tensor only if the mode is GatherMode::kDEFAULT.

The dimensions of the output likewise depends on the mode:

GatherMode::kDEFAULT:

    First nbElementwiseDims of output are computed by applying broadcast rules to
    first nbElementwiseDims of indices and data. Note that nbElementwiseDims <= 1.
    Rest of dimensions are computed by copying dimensions of Data, and replacing
    the dimension for axis gatherAxis with the dimensions of indices.

GatherMode::kND:
    If indices.d[q-1] = r - nbElementwiseDims
        output.d = [indices.d[0], ... , indices.d[q-2]]
    Else if indices.d[q-1] < r - nbElementWiseDims
        output.d = [indices.d[0], ... , indices.d[q-1], data.d[nbElementwiseDims + indices.d[q-1] + q],
        data.d[r-1]]
    Else
        This is build time error

GatherMode::kELEMENT:
    The output dimensions match the dimensions of the indices tensor.

The types of Data and Output must be the same, and Indices shall be DataType::kINT32.

How the elements of Data are gathered depends on the mode:

GatherMode::kDEFAULT:
    Each index in indices is used to index Data along axis gatherAxis.

GatherMode::kND:
    Indices is a rank q integer tensor, best thought of as a rank (q-1) tensor of
    indices into data, where each element defines a slice of data
    The operation can be formulated as output[i_1, ..., i_{q-1}] = data[indices[i_1, ..., i_{q-1}]]

GatherMode::kELEMENT:

    Here "axis" denotes the result of getGatherAxis().
    For each element X of indices:
        Let J denote a sequence for the subscripts of X
        Let K = sequence J with element [axis] replaced by X
        output[J] = data[K]

The handling of nbElementWiseDims depends on the mode:

GatherMode::kDEFAULT: nbElementWiseDims <= 1. Broadcast is supported across the elementwise dimension if present.
GatherMode::kND: 0 <= nbElementWiseDims < rank(Data)-1. Broadcast is not supported across the elementwise dimensions.
GatherMode::kELEMENT: nbElementWiseDims = 0

Notes:

For modes GatherMode::kND and GatherMode::kELEMENT, the first nbElementWiseDims dimensions of data and index must be equal. If not, an error will be reported at build time or run time.
Only mode GatherMode::kDEFAULT supports an implicit batch dimensions or broadcast on the elementwise dimensions.
If an axis of Data has dynamic length, using a negative index for it has undefined behavior.
No DLA support
Zero will be stored for OOB access

Warning: Do not inherit from this class, as doing so will break forward-compatibility of the API and ABI.

Constructor & Destructor Documentation

◆ ~IGatherLayer()

virtual nvinfer1::IGatherLayer::~IGatherLayer ( )

protectedvirtualdefaultnoexcept

Member Function Documentation

◆ getGatherAxis()

int32_t nvinfer1::IGatherLayer::getGatherAxis ( ) const

inlinenoexcept

Get the axis to gather on.

Warning: Undefined behavior when used with GatherMode::kND.

See also: setGatherAxis()

◆ getMode()

GatherMode nvinfer1::IGatherLayer::getMode ( ) const

inlinenoexcept

Get the gather mode.

See also: setMode()

◆ getNbElementWiseDims()

int32_t nvinfer1::IGatherLayer::getNbElementWiseDims ( ) const

inlinenoexcept

Get the number of leading dimensions of indices tensor to be handled elementwise.

See also: setNbElementWiseDims()

◆ setGatherAxis()

void nvinfer1::IGatherLayer::setGatherAxis ( int32_t axis )

inlinenoexcept

Set the axis used by GatherMode::kELEMENTS and GatherMode::kDEFAULT The axis must be less than the number of dimensions in the data input. The axis defaults to 0.

Warning: Undefined behavior when used with GatherMode::kND.

See also: getGatherAxis()

◆ setMode()

void nvinfer1::IGatherLayer::setMode ( GatherMode mode )

inlinenoexcept

Set the gather mode.

See also: getMode()

◆ setNbElementWiseDims()

void nvinfer1::IGatherLayer::setNbElementWiseDims ( int32_t elementWiseDims )

inlinenoexcept

Set the number of leading dimensions of indices tensor to be handled elementwise. The gathering of indexing starts from the dimension of data[NbElementWiseDims:]. The NbElementWiseDims must be less than the Rank of the data input.

Parameters

elementWiseDims number of dims to be handled as elementwise.

Default: 0

The value of nbElementWiseDims and GatherMode are checked during network validation:

GatherMode::kDEFAULT: nbElementWiseDims must be 0 if there is an implicit batch dimension. It can be 0 or 1 if there is not an implicit batch dimension. GatherMode::kND: nbElementWiseDims can be between 0 and one less than rank(data). GatherMode::kELEMENT: nbElementWiseDims must be 0

See also: getNbElementWiseDims()

Member Data Documentation

◆ mImpl

apiv::VGatherLayer* nvinfer1::IGatherLayer::mImpl

protected

The documentation for this class was generated from the following file:

NvInfer.h

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ~IGatherLayer()

Member Function Documentation

◆ getGatherAxis()

◆ getMode()

◆ getNbElementWiseDims()

◆ setGatherAxis()

◆ setMode()

◆ setNbElementWiseDims()

Member Data Documentation

◆ mImpl