---
title: "init(_:)"
framework: simd
role: symbol
role_heading: Initializer
path: "simd/simd_quatd/init(_:)-791zk"
---

# init(_:)

Creates a new quaternion from a 3 x 3 rotation matrix.

## Declaration

```swift
init(_ rotationMatrix: simd_double3x3)
```

## Parameters

- `rotationMatrix`: The rotation matrix that must be orthogonal and have a determinant of 1.

## See Also

### Initializing a quaternion

- [init()](simd/simd_quatd/init().md)
- [init(vector:)](simd/simd_quatd/init(vector:).md)
- [init(_:)](simd/simd_quatd/init(_:)-5vcd5.md)
- [init(angle:axis:)](simd/simd_quatd/init(angle:axis:).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)