GELU- Gaussian Error Linear Unit¶

Versioned name : Gelu-2

Category : Activation function

Short description : Gaussian error linear unit element-wise activation function.

Detailed description

Gelu operation is introduced in this article. It performs element-wise activation function on a given input tensor, based on the following mathematical formula:

$Gelu(x) = x\cdot\Phi(x) = x\cdot\frac{1}{2}\cdot\left[1 + erf\left(x/\sqrt{2}\right)\right]$

where Φ(x) is the Cumulative Distribution Function for Gaussian Distribution.

Additionally, Gelu function may be approximated as follows:

$Gelu(x) \approx 0.5\cdot x\cdot \left(1 + \tanh\left[\sqrt{2/\pi} \cdot (x + 0.044715 \cdot x^3)\right]\right)$

Attributes : Gelu operation has no attributes.

Inputs :

• 1 : A tensor of type T and arbitrary shape. Required.

Outputs :

• 1 : The result of element-wise Gelu function applied to the input tensor. A tensor of type T and the same shape as input tensor.

Types

• T : arbitrary supported floating-point type.

Example

<layer ... type="Gelu">
<input>
<port id="0">
<dim>1</dim>
<dim>128</dim>
</port>
</input>
<output>
<port id="1">
<dim>1</dim>
<dim>128</dim>
</port>
</output>
</layer>