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−## Copyright (C) 1996-2012 John W. Eaton
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−##
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−## This file is part of Octave.
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−##
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−## Octave is free software; you can redistribute it and/or modify it
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−## under the terms of the GNU General Public License as published by
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−## the Free Software Foundation; either version 3 of the License, or (at
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−## your option) any later version.
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−##
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−## Octave is distributed in the hope that it will be useful, but
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−## WITHOUT ANY WARRANTY; without even the implied warranty of
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−## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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−## General Public License for more details.
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−##
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−## You should have received a copy of the GNU General Public License
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−## along with Octave; see the file COPYING.  If not, see
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−## <http://www.gnu.org/licenses/>.
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−
+
−## -*- texinfo -*-
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−## @deftypefn  {Function File} {} is_leap_year ()
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−## @deftypefnx {Function File} {} is_leap_year (@var{year})
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−## Return true if @var{year} is a leap year and false otherwise.  If no
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−## year is specified, @code{is_leap_year} uses the current year.
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−## For example:
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−##
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−## @example
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−## @group
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−## is_leap_year (2000)
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−##    @result{} 1
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−## @end group
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−## @end example
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−## @seealso{weekday, eomday, calendar}
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−## @end deftypefn
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−
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−## Author: jwe
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−
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−function retval = is_leap_year (year)
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−
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−  if (nargin > 1)
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−    print_usage ();
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−  endif
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−
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−  if (nargin == 0)
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−    t = clock ();
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−    year = t(1);
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−  endif
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−
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−  retval = (rem (year, 4) == 0 & rem (year, 100) != 0) | (rem (year, 400) == 0);
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−
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−endfunction
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−
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−
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−%!assert (is_leap_year (2000), true)
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−%!assert (is_leap_year (1976), true)
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−%!assert (is_leap_year (1000), false)
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−%!assert (is_leap_year (1800), false)
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−%!assert (is_leap_year (1600), true)
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−
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−%!error is_leap_year (1, 2)
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−