/usr/share/octave/packages/interval-2.1.0/@infsup/hypot.m is in octave-interval 2.1.0-2.
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##
## This program 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.
##
## This program 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 this program; if not, see <http://www.gnu.org/licenses/>.
## -*- texinfo -*-
## @documentencoding UTF-8
## @defmethod {@@infsup} hypot (@var{X}, @var{Y})
##
## Compute the euclidean norm.
##
## @code{hypot (@var{x}, @var{y}) = sqrt (@var{x}^2 + @var{y}^2)}
##
## Accuracy: The result is a tight enclosure.
##
## @example
## @group
## x = infsup (2, 3);
## y = infsup (1, 2);
## hypot (x, y)
## @result{} ans ⊂ [2.236, 3.6056]
## @end group
## @end example
## @end defmethod
## Author: Oliver Heimlich
## Keywords: interval
## Created: 2015-02-20
function x = hypot (x, y)
if (nargin ~= 2)
print_usage ();
return
endif
if (not (isa (x, "infsup")))
x = infsup (x);
endif
if (not (isa (y, "infsup")))
y = infsup (y);
endif
l = mpfr_function_d ('hypot', -inf, mig (x), mig (y));
u = mpfr_function_d ('hypot', +inf, mag (x), mag (y));
emptyresult = isempty (x) | isempty (y);
l(emptyresult) = inf;
u(emptyresult) = -inf;
l(l == 0) = -0;
x.inf = l;
x.sup = u;
endfunction
%!# from the documentation string
%!assert (hypot (infsup (2, 3), infsup (1, 2)) == "[0x1.1E3779B97F4A7p1, 0x1.CD82B446159F4p1]");
%!# correct use of signed zeros
%!test
%! x = hypot (infsup (0), infsup (0));
%! assert (signbit (inf (x)));
%! assert (not (signbit (sup (x))));
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