how to represent 30, 60, and 45 degree on matrix in Matlab?

i want to represent 30 degree,60 degree and 90 degree on matlab? just like 45 degree is represented as

[-1,-1,2;-1,2,-1;2,-1,-1]

[Adam]

Clearly it can't be done in exact form because matrix elements only have 8 neighbours each at angles of 45 degrees apart.

[Prerna Surbhi]

i want to implement 30,60 and 90 degree line detection in an image,just like 45 degree line detection can be done by using [-1 -1 2;-1 2 -1;2 -1 -1];

[Walter Roberson]

How is that matrix being used? Is it, for example, the mask being used for conv2() ?

Answer 1

[CS Researcher]

You should always give out as much information related to your question as you can. Help us to help you. I did not completely understand what you mean by representing angles in MATLAB. It is extremely vague. Do you mean rotation matrix? If yes, then it is given by (for a 3 x 3 case)

R = [ 1      0            0
      0  cos(theta)   sin(theta)
      0  -sin(theta)  cos(theta)]

The theta is in radians. How did you get the matrix that you have for 45 degrees?