Hy, I need to calculate angle from 2x2 rotation matrix. How exactly i can do that?
Thank you, for help.
You mean this kind of rotation matrix?
$\displaystyle \begin{bmatrix} \cos \theta & -\sin \theta \\ \sin \theta & \cos \theta \\ \end{bmatrix}$
Rotation matrix - Wikipedia, the free encyclopedia
You can derive the rotation matrix by considering what (1,0) and (0,1) map to when rotated by angle theta.
If you have a matrix of that form and need to find theta, you can do so using inverse trig functions.
Jep this form i mean.
This will look weird but i just want to get sure its correct.
$\displaystyle \begin{bmatrix} acos(\cos \theta) & asin(--\sin \theta) \\ asin(\sin \theta) & acos(\cos \theta) \\ \end{bmatrix}$
and all elements must be the same if i am not mistaking.