modulo 2 pi?

[Søren Hauberg]

Hi All,

If I have two angles 'theta' and 'psi', and I want to compute their
difference I can simply do

  d = theta - psi;

However, I'd like this result to be in the range [0, 2*pi]. Can I simply
do

  d = mod (theta - psi, 2*pi);

or will this fail in some cases?

Thanks,
Søren