function  result = jsn ( x, k )

%*****************************************************************************80
%
%% jsn() evaluates the Jacobi elliptic function sn(x,k).
%
%  Discussion:
%
%    Compute value of the Jacobi elliptic function sn(x,k) for
%    argument |x|<inf and elliptic modulus |k|<inf. Returns NaN if any of
%    the arguments is invalid or convergence failed. It is assumed that 
%    arguments are real scalars without check.
%
  [result, ~, ~] = sncndn( x, (1 - k)*(1 + k));
  
  return  
end

