GELU

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:

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

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

Additionally, the 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>