# nn_prelu: PReLU module In torch: Tensors and Neural Networks with 'GPU' Acceleration

## Description

Applies the element-wise function:

\mbox{PReLU}(x) = \max(0,x) + a * \min(0,x)

or

\mbox{PReLU}(x) = ≤ft\{ \begin{array}{ll} x, & \mbox{ if } x ≥q 0 \\ ax, & \mbox{ otherwise } \end{array} \right.

## Usage

 1 nn_prelu(num_parameters = 1, init = 0.25) 

## Arguments

 num_parameters (int): number of a to learn. Although it takes an int as input, there is only two values are legitimate: 1, or the number of channels at input. Default: 1 init (float): the initial value of a. Default: 0.25

## Details

Here a is a learnable parameter. When called without arguments, nn.prelu() uses a single parameter a across all input channels. If called with nn_prelu(nChannels), a separate a is used for each input channel.

## Shape

• Input: (N, *) where * means, any number of additional dimensions

• Output: (N, *), same shape as the input

## Attributes

• weight (Tensor): the learnable weights of shape (num_parameters).

## Note

weight decay should not be used when learning a for good performance.

Channel dim is the 2nd dim of input. When input has dims < 2, then there is no channel dim and the number of channels = 1.

## Examples

 1 2 3 4 5 6 if (torch_is_installed()) { m <- nn_prelu() input <- torch_randn(2) output <- m(input) } 

torch documentation built on Oct. 7, 2021, 9:22 a.m.