---
title: BNNSActivationFunctionGELUApproximation2
framework: accelerate
role: symbol
role_heading: Global Variable
path: accelerate/bnnsactivationfunctiongeluapproximation2
---

# BNNSActivationFunctionGELUApproximation2

An activation function that provides a fast evaluation of the Gaussian error linear units (GELU) approximation on its input.

## Declaration

```swift
var BNNSActivationFunctionGELUApproximation2: BNNSActivationFunction { get }
```

## Discussion

Discussion This constant defines an activation function that returns values using the following operation: x * (ReLU 6(x + 3.0) * 1.0 / 6.0) The following illustrates the output that the activation function generates from inputs in the range -10...10, an alpha of 0.1, and a beta of 1.0. The thinner, dashed line shows, for comparison, the result of BNNSActivationFunctionGELUApproximation using the same alpha and beta values:

## See Also

### Raw Values

- [init(_:)](accelerate/bnnsactivationfunction/init(_:).md)
- [init(rawValue:)](accelerate/bnnsactivationfunction/init(rawvalue:).md)
- [rawValue](accelerate/bnnsactivationfunction/rawvalue.md)
- [BNNSActivationFunctionAbs](accelerate/bnnsactivationfunctionabs.md)
- [BNNSActivationFunctionCELU](accelerate/bnnsactivationfunctioncelu.md)
- [BNNSActivationFunctionClampedLeakyRectifiedLinear](accelerate/bnnsactivationfunctionclampedleakyrectifiedlinear.md)
- [BNNSActivationFunctionELU](accelerate/bnnsactivationfunctionelu.md)
- [BNNSActivationFunctionErf](accelerate/bnnsactivationfunctionerf.md)
- [BNNSActivationFunctionGELU](accelerate/bnnsactivationfunctiongelu.md)
- [BNNSActivationFunctionGELUApproximation](accelerate/bnnsactivationfunctiongeluapproximation.md)
- [BNNSActivationFunctionGELUApproximationSigmoid](accelerate/bnnsactivationfunctiongeluapproximationsigmoid.md)
- [BNNSActivationFunctionGumbel](accelerate/bnnsactivationfunctiongumbel.md)
- [BNNSActivationFunctionGumbelMax](accelerate/bnnsactivationfunctiongumbelmax.md)
- [BNNSActivationFunctionHardShrink](accelerate/bnnsactivationfunctionhardshrink.md)
- [BNNSActivationFunctionHardSigmoid](accelerate/bnnsactivationfunctionhardsigmoid.md)