# Pad a list of variable length Tensors with `padding_value`

Source: `R/nn-utils-rnn.R`

`nn_utils_rnn_pad_sequence.Rd`

`pad_sequence`

stacks a list of Tensors along a new dimension,
and pads them to equal length. For example, if the input is list of
sequences with size `L x *`

and if batch_first is False, and `T x B x *`

otherwise.

## Arguments

- sequences
`(list[Tensor])`

: list of variable length sequences.- batch_first
(bool, optional): output will be in

`B x T x *`

if`TRUE`

, or in`T x B x *`

otherwise- padding_value
(float, optional): value for padded elements. Default: 0.

## Details

`B`

is batch size. It is equal to the number of elements in `sequences`

.
`T`

is length of the longest sequence.
`L`

is length of the sequence.
`*`

is any number of trailing dimensions, including none.

## Note

This function returns a Tensor of size `T x B x *`

or `B x T x *`

where `T`

is the length of the longest sequence. This function assumes
trailing dimensions and type of all the Tensors in sequences are same.

## Examples

```
if (torch_is_installed()) {
a <- torch_ones(25, 300)
b <- torch_ones(22, 300)
c <- torch_ones(15, 300)
nn_utils_rnn_pad_sequence(list(a, b, c))$size()
}
#> [1] 25 3 300
```