// 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 x=sinm(a)
    //   sinm - computes the matrix sine
    //%CALLING SEQUENCE
    //   x=sinm(a)
    //%PARAMETERS
    //   a   : square  matrix
    //   x   : square  matrix

    rhs = argn(2);

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

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

    if a==[] then x=[],return,end

    if norm(imag(a),1)==0 then
        x=imag(expm(%i*a));
    else
        x=-0.5*%i*(expm(%i*a)-expm(-%i*a));
    end

endfunction