I have the function:
x(\phi) = \left[(\phi - \phi_0)\frac{72~000}{360^\circ} + x_0\right]~\textrm{mod}~72~000
and I'm wondering how to invert it in order to get \phi(x) ? Also, the modulus operator is not exactly what I'm looking for here, because if x goes below 0, I want it to wrap around...