---
title: "simd_axis(_:)"
framework: simd
role: symbol
role_heading: Function
path: "simd/simd_axis(_:)-56smw"
---

# simd_axis(_:)

## Declaration

```swift
func simd_axis(_ q: simd_quath) -> simd_half3
```

## Discussion

Discussion The normalized axis (a 3-element vector) around which the action of the quaternion q rotates.