elliptic function

An elliptic function is an analytic function from C\mathbb{C} to C\mathbb{C} which is doubly periodic. That is, for two independent values of the complex number ww, the functions f(z)f(z) and f(w+z)f(w + z) are the same.
It can also be regarded as the inverse function to certain integrals (called elliptic integrals) of the form ellip int where RR is a polynomial of degree 3 or 4.