Complex Dilogarithm

Dilogarithm of any complex numbers

dilog(z) returns the (component-wise) dilogarithm of z. It is quite fast and accurate (around machine precision).

The present dilog function corresponds to Maple's polylog(2,z) and Mathematica's PolyLog[2,z] functions.

It is defined as
dilog(z) = sum_{n=1}^Inf z^n/n^2
for |z|<=1, and by analytic continuation for |z|>1.