# Reverse-mode autodiff with Enzyme involving WignerSymbols

**URL:** https://discourse.julialang.org/t/reverse-mode-autodiff-with-enzyme-involving-wignersymbols/123967
**Category:** General Usage
**Tags:** question
**Created:** [December 18, 2024, 5:12pm UTC](https://discourse.julialang.org/t/reverse-mode-autodiff-with-enzyme-involving-wignersymbols/123967 "2024-12-18T17:12:30Z")
**Posts on this page:** 1
**Showing post:** 2

<div class="post-metadata">

### Author: ![cdawg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/cdawg/32/9811_2.png) [@cdawg](https://discourse.julialang.org/u/cdawg)
#### Post date: [December 18, 2024, 6:35pm UTC](https://discourse.julialang.org/t/reverse-mode-autodiff-with-enzyme-involving-wignersymbols/123967/2 "2024-12-18T18:35:38Z")

</div>

```julia
>>> typeof(cg)

RationalRoots.RationalRoot{BigInt}

```

So this is a pretty memory flexiblly sized type which helps say meson calculations perfectly cancel where theres a symmetry. If you just want a float64 maybe look at the options here [Timing Clebsch-Gordan-coefficients calls in Julia (beating c++ again) - #3 by misha\_mikhasenko](https://discourse.julialang.org/t/timing-clebsch-gordan-coefficients-calls-in-julia-beating-c-again/32736/3).

edit: or this one looks good and has specific float operations [GitHub - 0382/CGcoefficient.jl: Compute CG coefficient, Racah coefficient, and Wigner 3j, 6j, 9j Symbols, and give the exact results.](https://github.com/0382/CGcoefficient.jl)

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