// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) INRIA
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution.  The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt

function [t]=tanh(z)
    //
    //  PURPOSE
    //    element wise hyperbolic tangent
    //
    //  METHOD
    //    based on the formula  tanh(z) = -i tan(i z)
    //

    rhs = argn(2);

    if rhs <> 1 then
        error(msprintf(gettext("%s: Wrong number of input argument(s): %d expected.\n"),"tanh",1));
    end

    if type(z)<>1 then
        error(msprintf(gettext("%s: Wrong type for input argument #%d: Real or complex matrix expected.\n"),"tanh",1));
    end

    if isreal(z) then
        t = imag(tan(imult(z)));
    else
        t = -imult(tan(imult(z)));
    end

endfunction