Theta phi positive and negative conventions and conversions

Hi, how can I convert any (theta_i,phi_i) angular coordinate so that it is restricted only to values where theta_i goes from 0º to 180º and phi from 0º to 360º ? My inmediate answer would be just to add 360º to any negative angle, but this may not be completely correct because it is possible that I need to change the other angle even if positive? Thanks

Answer 1

[Alan Stevens]

Try

mod(theta,180)

and

mod(phi,360)

[Albert]

Thanks! I may need to think further on this, because it's a matter of coordinate system definition in fact. If I define theta -90 to 90 instead of 0 to 180, then maybe the phi angle needs to adapt accordingly. Other than that your answer makes sense.