---
title: "init(angle:axis:)"
framework: simd
role: symbol
role_heading: Initializer
path: "simd/simd_quatd/init(angle:axis:)"
---

# init(angle:axis:)

Creates a new quaternion with an action that’s a rotation about an axis.

## Declaration

```swift
init(angle: Double, axis: SIMD3<Double>)
```

## Parameters

- `angle`: The rotation angle in radians.
- `axis`: A three-element vector that specifies the rotation axis.

## See Also

### Initializing a quaternion

- [init()](simd/simd_quatd/init().md)
- [init(vector:)](simd/simd_quatd/init(vector:).md)
- [init(_:)](simd/simd_quatd/init(_:)-791zk.md)
- [init(_:)](simd/simd_quatd/init(_:)-5vcd5.md)
- [init(from:to:)](simd/simd_quatd/init(from:to:).md)
- [init(ix:iy:iz:r:)](simd/simd_quatd/init(ix:iy:iz:r:).md)
- [init(real:imag:)](simd/simd_quatd/init(real:imag:).md)