function y = cotangent(z)

%COT    Cotangent.
%   COT(X) is the cotangent of the elements of X.
%
% removes a bug in MATLAB Version 6.5.0.180913a (R13)

large = 20;

y = z;
k1 = find(abs(imag(z)) > large);
k2 = find(abs(imag(z)) <= large);
y(k2) = 1./tan(z(k2));
y(k1) = -i*sign(imag(z(k1)));

return