Function problem

How to express jacobian elliptic function in ff.
sn-1 is the inverse function of sn.k is a constant and I need to express the function y=snx.
Thank you so much for any help.

The Jacobian Elliptic functions are defined in GSL and gsl is interfaced in freefem via the GSL plugin. However, if you check the gsl.idp plugin, you can see that gsl_sf_elljac_e (in the freefem language it’s gslsfelljace) is not listed there. So this means it is not added yet. I think this should be easily added, in the file plugin/seq/ff_gsl_awk.hpp.
(I cannot do more right now) I hope this helps

Thank you for your response! Maybe I should try another way.