@cindex Jacobi elliptic functions@cindex elliptic functions (Jacobi)The Jacobian Elliptic functions are defined in Abramowitz & Stegun,Chapter 16.  The functions are declared in the header file@file{gsl_sf_elljac.h}.@deftypefun int gsl_sf_elljac_e (double @var{u}, double @var{m}, double * @var{sn}, double * @var{cn}, double * @var{dn})This function computes the Jacobian elliptic functions @math{sn(u|m)},@math{cn(u|m)}, @math{dn(u|m)} by descending Landentransformations.@comment Exceptional Return Values: GSL_EDOM@end deftypefun