Hello,

I have an `itk::Transform`

(specifically an `itk::AffineTransform`

). I would like to know how much this transform rotates the Z-axis - i.e. the angle between (0,0,1) and the result of applying the transform to (0,0,1).

What is the most straight forward way to calculate this? Apply the transform and then calculate the dot product of the result with (0,0,1)? I feel like I am missing a more obvious way.