/usr/share/octave/packages/interval-3.1.0/@infsupdec/cbrt.m is in octave-interval 3.1.0-5.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | ## Copyright 2015-2016 Oliver Heimlich
##
## 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 {@@infsupdec} cbrt (@var{X})
##
## Compute the cube root.
##
## Accuracy: The result is a tight enclosure.
##
## @example
## @group
## cbrt (infsupdec (-27, 27))
## @result{} ans = [-3, +3]_com
## @end group
## @end example
## @seealso{@@infsupdec/realsqrt, @@infsupdec/nthroot}
## @end defmethod
## Author: Oliver Heimlich
## Keywords: interval
## Created: 2015-03-15
function result = cbrt (x)
if (nargin ~= 1)
print_usage ();
return
endif
result = newdec (cbrt (x.infsup));
result.dec = min (result.dec, x.dec);
endfunction
%!# from the documentation string
%!assert (isequal (cbrt (infsupdec (-27, 27)), infsupdec (-3, 3)));
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