# Activation functions

Customized activation functions for supporting various models in 🤗 Diffusers.

## GELU[[diffusers.models.activations.GELU]]

- **dim_in** (`int`) -- The number of channels in the input.
- **dim_out** (`int`) -- The number of channels in the output.
- **approximate** (`str`, *optional*, defaults to `"none"`) -- If `"tanh"`, use tanh approximation.
- **bias** (`bool`, defaults to True) -- Whether to use a bias in the linear layer.

GELU activation function with tanh approximation support with `approximate="tanh"`.

## GEGLU[[diffusers.models.activations.GEGLU]]

- **dim_in** (`int`) -- The number of channels in the input.
- **dim_out** (`int`) -- The number of channels in the output.
- **bias** (`bool`, defaults to True) -- Whether to use a bias in the linear layer.

A [variant](https://huggingface.co/papers/2002.05202) of the gated linear unit activation function.

## ApproximateGELU[[diffusers.models.activations.ApproximateGELU]]

- **dim_in** (`int`) -- The number of channels in the input.
- **dim_out** (`int`) -- The number of channels in the output.
- **bias** (`bool`, defaults to True) -- Whether to use a bias in the linear layer.

The approximate form of the Gaussian Error Linear Unit (GELU). For more details, see section 2 of this
[paper](https://huggingface.co/papers/1606.08415).

## SwiGLU[[diffusers.models.activations.SwiGLU]]

- **dim_in** (`int`) -- The number of channels in the input.
- **dim_out** (`int`) -- The number of channels in the output.
- **bias** (`bool`, defaults to True) -- Whether to use a bias in the linear layer.

A [variant](https://huggingface.co/papers/2002.05202) of the gated linear unit activation function. It's similar to
`GEGLU` but uses SiLU / Swish instead of GeLU.

## FP32SiLU[[diffusers.models.activations.FP32SiLU]]

SiLU activation function with input upcasted to torch.float32.

## LinearActivation[[diffusers.models.activations.LinearActivation]]