---
title: "act(_:)"
framework: simd
role: symbol
role_heading: Instance Method
path: "simd/simd_quatd/act(_:)"
---

# act(_:)

Returns the specified vector rotated by the quaternion.

## Declaration

```swift
func act(_ vector: SIMD3<Double>) -> SIMD3<Double>
```

## See Also

### Applying geometric operations to quaternions

- [simd_act(_:_:)](simd/simd_act(_:_:)-47h09.md)
- [simd_angle(_:)](simd/simd_angle(_:)-zuvx.md)
- [simd_axis(_:)](simd/simd_axis(_:)-56wf4.md)
- [simd_bezier(_:_:_:_:_:)](simd/simd_bezier(_:_:_:_:_:)-556xd.md)
- [simd_conjugate(_:)](simd/simd_conjugate(_:)-98awl.md)
- [simd_imag(_:)](simd/simd_imag(_:)-2c7fz.md)
- [simd_negate(_:)](simd/simd_negate(_:)-3ysgu.md)
- [simd_real(_:)](simd/simd_real(_:)-75t5f.md)
- [simd_slerp(_:_:_:)](simd/simd_slerp(_:_:_:)-65dt5.md)
- [simd_slerp_longest(_:_:_:)](simd/simd_slerp_longest(_:_:_:)-8hbz2.md)
- [simd_spline(_:_:_:_:_:)](simd/simd_spline(_:_:_:_:_:)-19wbg.md)
- [simd_dot(_:_:)](simd/simd_dot(_:_:)-2bnqp.md)
- [dot(_:_:)](simd/dot(_:_:)-438xp.md)
- [simd_length(_:)](simd/simd_length(_:)-52o29.md)
- [simd_normalize(_:)](simd/simd_normalize(_:)-ud11.md)