Currently uses WIGXJPF 1.11

A fork of jagot’s WIGXJPF.jl with parallelization & more up-to-date WIGXJPF.

The original was deprecated in favour of WignerSymbols.jl I’ve shifted to using Wigxjpf_jll instead of building the library directly. I will try to get WIGXJPF updated in Yggdrasil

This is a Julia wrapper for the WIGXJPF library used to calculate Wigner 3j, 6j and 9j symbols. Since the original library is release under the GPLv3 license, so is this Julia wrapper.

The original library expects all arguments to multiplied by two but the wrapper handles that internally. For instance, to calculate the 3j symbol (1 1 0; 0 0 0) = -1/√3, one would say

wig3j(1, 1, 0,
      0, 0, 0)

-0.5773502691896258

It also works for rational arguments:

wig3j(1//2,  1//2, 0,
      1//2, -1//2, 0)

0.7071067811865475