% COTH COTH Hyperbolic Cotangent Function
% 
% Usage
% 
% Computes the hyperbolic cotangent of the argument.
% The syntax for its use is
% 
%    y = coth(x)
% 
function y = coth(x)
  if (nargin == 0 || ~isnumeric(x))
    error('coth expects a numeric input');
  end
  y = 1.0f./tanh(x);