---
title: activation
framework: metalperformanceshadersgraph
role: symbol
role_heading: Instance Property
path: metalperformanceshadersgraph/mpsgraphlstmdescriptor/activation
---

# activation

A parameter that defines the activation function used with the current cell value of the LSTM operation.

## Declaration

```swift
var activation: MPSGraphRNNActivation { get set }
```

## Discussion

Discussion Default value: MPSGraphRNNActivationTanh.