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Activation Functions

An activation function introduces non-linearity into a neuron's output, enabling the network to approximate complex functions. Common choices are ReLU, GELU, and SiLU (SwiGLU).

What is Activation Functions?

An activation function introduces non-linearity into a neuron's output, enabling the network to approximate complex functions. Common choices are ReLU, GELU, and SiLU (SwiGLU).

An activation function introduces non-linearity into a neuron's output, enabling the network to approximate complex functions. Common choices are ReLU, GELU, and SiLU (SwiGLU).

Where is it used?

Transformers use GELU (GPT-2) or SiLU within SwiGLU (Llama, PaLM) in their MLP layers; without nonlinearity, stacking layers would collapse into a single linear map.

How to build it

Plot `F.relu`, `F.gelu`, and `F.silu` over `torch.linspace(-5,5,100)` with matplotlib, and build a 2-layer net with and without activation to show nonlinearity's effect.

Code

A practical example:

example.pypython