## Copyright (C) 2006-2019 David Bateman
##
## This file is part of Octave.
##
## Octave is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <https://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {} {} secd (@var{x})
## Compute the secant for each element of @var{x} in degrees.
## @seealso{asecd, sec}
## @end deftypefn

## Author: David Bateman <dbateman@free.fr>

function y = secd (x)

  if (nargin != 1)
    print_usage ();
  endif

  y = 1 ./ cosd (x);

endfunction


%!assert (secd (0:10:80), sec (pi*[0:10:80]/180), -10*eps)
%!assert (secd ([0, 180, 360]) != Inf)
%!assert (secd ([90, 270]) == Inf)

%!error secd ()
%!error secd (1, 2)