ReverseSequence

public final class ReverseSequence

Reverses variable length slices.

This op first slices `input` along the dimension `batch_dim`, and for each slice `i`, reverses the first `seq_lengths[i]` elements along the dimension `seq_dim`.

The elements of `seq_lengths` must obey `seq_lengths[i] <= input.dims[seq_dim]`, and `seq_lengths` must be a vector of length `input.dims[batch_dim]`.

The output slice `i` along dimension `batch_dim` is then given by input slice `i`, with the first `seq_lengths[i]` slices along dimension `seq_dim` reversed.

For example:

# Given this:
 batch_dim = 0
 seq_dim = 1
 input.dims = (4, 8, ...)
 seq_lengths = [7, 2, 3, 5]
 
 # then slices of input are reversed on seq_dim, but only up to seq_lengths:
 output[0, 0:7, :, ...] = input[0, 7:0:-1, :, ...]
 output[1, 0:2, :, ...] = input[1, 2:0:-1, :, ...]
 output[2, 0:3, :, ...] = input[2, 3:0:-1, :, ...]
 output[3, 0:5, :, ...] = input[3, 5:0:-1, :, ...]
 
 # while entries past seq_lens are copied through:
 output[0, 7:, :, ...] = input[0, 7:, :, ...]
 output[1, 2:, :, ...] = input[1, 2:, :, ...]
 output[2, 3:, :, ...] = input[2, 3:, :, ...]
 output[3, 2:, :, ...] = input[3, 2:, :, ...]

In contrast, if:

# Given this:
 batch_dim = 2
 seq_dim = 0
 input.dims = (8, ?, 4, ...)
 seq_lengths = [7, 2, 3, 5]
 
 # then slices of input are reversed on seq_dim, but only up to seq_lengths:
 output[0:7, :, 0, :, ...] = input[7:0:-1, :, 0, :, ...]
 output[0:2, :, 1, :, ...] = input[2:0:-1, :, 1, :, ...]
 output[0:3, :, 2, :, ...] = input[3:0:-1, :, 2, :, ...]
 output[0:5, :, 3, :, ...] = input[5:0:-1, :, 3, :, ...]
 
 # while entries past seq_lens are copied through:
 output[7:, :, 0, :, ...] = input[7:, :, 0, :, ...]
 output[2:, :, 1, :, ...] = input[2:, :, 1, :, ...]
 output[3:, :, 2, :, ...] = input[3:, :, 2, :, ...]
 output[2:, :, 3, :, ...] = input[2:, :, 3, :, ...]

Nested Classes

class ReverseSequence.Options Optional attributes for ReverseSequence

Constants

String OP_NAME The name of this op, as known by TensorFlow core engine

Public Methods

Output<T>	asOutput() Returns the symbolic handle of the tensor.
static ReverseSequence.Options	batchDim(Long batchDim)
static <T extends TType> ReverseSequence<T>	create(Scope scope, Operand<T> input, Operand<? extends TNumber> seqLengths, Long seqDim, Options... options) Factory method to create a class wrapping a new ReverseSequence operation.
Output<T>	output() The partially reversed input.

Inherited Methods

From class org.tensorflow.op.RawOp

final boolean	equals(Object obj)
final int	hashCode()
Operation	op() Return this unit of computation as a single `Operation`.
final String	toString()

From class java.lang.Object

boolean	equals(Object arg0)
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

From interface org.tensorflow.op.Op

abstract ExecutionEnvironment	env() Return the execution environment this op was created in.
abstract Operation	op() Return this unit of computation as a single `Operation`.

From interface org.tensorflow.Operand

abstract Output<T>	asOutput() Returns the symbolic handle of the tensor.
abstract T	asTensor() Returns the tensor at this operand.
abstract Shape	shape() Returns the (possibly partially known) shape of the tensor referred to by the `Output` of this operand.
abstract Class<T>	type() Returns the tensor type of this operand

From interface org.tensorflow.ndarray.Shaped

abstract int	rank()
abstract Shape	shape()
abstract long	size() Computes and returns the total size of this container, in number of values.

Constants

public static final String OP_NAME

The name of this op, as known by TensorFlow core engine

Constant Value: "ReverseSequence"

Public Methods

public Output<T> asOutput ()

Returns the symbolic handle of the tensor.

Inputs to TensorFlow operations are outputs of another TensorFlow operation. This method is used to obtain a symbolic handle that represents the computation of the input.

public static ReverseSequence.Options batchDim (Long batchDim)

Parameters

batchDim	The dimension along which reversal is performed.

public static ReverseSequence<T> create (Scope scope, Operand<T> input, Operand<? extends TNumber> seqLengths, Long seqDim, Options... options)

Factory method to create a class wrapping a new ReverseSequence operation.

Parameters

scope	current scope
input	The input to reverse.
seqLengths	1-D with length `input.dims(batch_dim)` and `max(seq_lengths) <= input.dims(seq_dim)`
seqDim	The dimension which is partially reversed.
options	carries optional attributes values

Returns

a new instance of ReverseSequence

public Output<T> output ()

The partially reversed input. It has the same shape as `input`.