How can I do a Method which returns a Rotation Matrix?

Hello,

I want to implement the method rotTheta(phi, theta), which returns a rotation matrix containing a vector when multiplied ¨ φ degrees about an axis rotates, which is defined by y = x tan(θ).

I know how to implement a rotation matrix over the x,y- and z-axis but I'm not sure how to do the mentioned method. It would be a pleasure if you could help me.

Answer 1

[Torsten]

syms theta phi
M = [cos(theta) -sin(theta) 0;sin(theta) cos(theta) 0;0 0 1]*[1 0 0;0 cos(phi) -sin(phi);0 sin(phi) cos(phi)]*[cos(theta) sin(theta) 0;-sin(theta) cos(theta) 0;0 0 1]

M = 

[Faruk Alioglu]

Thank you very much, could you also explain what you did?

[Torsten]

1. Rotate by -theta about the z-axis to make your axis of rotation y = tan(theta)*x to fit with the x-axis (M1).
2. Rotate by phi about the x-axis (M2).
3. Rotate back by theta about the z-axis (M3).
4. The complete rotation is then described by M = M3*M2*M1.