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

# inputGateActivation

A parameter that defines the activation function used with the input gate of the LSTM operation.

## Declaration

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

## Discussion

Discussion Default value: MPSGraphRNNActivationSigmoid.