(sw-rotmat)=

# sw_rotmat

## Syntax
  
`R = sw_rotmat(rotAxis,rotAngle)`
 
## Description
  
`R = sw_rotmat(rotAxis,rotAngle)` produces the `R` rotation matrix that
rotates any vector around the given `rotAxis` rotation axis by `rotAngle`
angle in radian. Positive rotation is the right-hand direction around the
rotation axis and using the following rotation formula:
```matlab
VR = R*V
```
 
To rotate tensors ($3\times 3$ matrices) use the following formula:
```matlab
Mp = R * M * R';
```
 
## Input Arguments
  
`rotAxis`
: Axis of rotation, stored in a row vector with 3 elements.
  
`rotAngle`
: Angle of rotation in radian, can be also a row vector with $n_{ang}$
  number of elements.
  
## Output Arguments
  
`R`
: Rotation matrix with dimensions of $[3\times 3]$ if a single rotation
  angle is given. If `rotAngle` is a vector, `R` will contain a
  rotation matrix for each angle, it's dimensions are $[3\times 3\times
  n_{ang}]$.
 
## See Also
  
[sw_rot](#sw-rot) \| [sw_mirror](#sw-mirror)