/usr/share/octave/packages/interval-3.1.0/@infsup/intervaltotext.m is in octave-interval 3.1.0-5.
This file is owned by root:root, with mode 0o644.
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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 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | ## Copyright 2014-2016 Oliver Heimlich
## Copyright 2017 Joel Dahne
##
## 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
## @deftypemethod {@@infsup} {@var{S} =} intervaltotext (@var{X})
## @deftypemethodx {@@infsup} {@var{S} =} intervaltotext (@var{X}, @var{FORMAT})
##
## Build an approximate representation of the interval @var{X}.
##
## Output @var{S} is a simple string for scalar intervals, and a cell array of
## strings for interval arrays.
##
## The interval boundaries are stored in binary floating point format and are
## converted to decimal or hexadecimal format with possible precision loss. If
## output is not exact, the boundaries are rounded accordingly (e. g. the upper
## boundary is rounded towards infinite for output representation).
##
## The exact decimal format may produce a lot of digits.
##
## Possible values for @var{FORMAT} are: @code{decimal} (default),
## @code{exact decimal}, @code{exact hexadecimal}, @code{auto}
##
## Accuracy: For all intervals @var{X} is an accurate subset of
## @code{infsup (intervaltotext (@var{X}))}.
## @example
## @group
## x = infsup (1 + eps);
## intervaltotext (x)
## @result{} [1.0000000000000002, 1.000000000000001]
## @end group
## @end example
## @example
## @group
## y = nextout (x);
## intervaltotext (y)
## @result{} [1, 1.0000000000000005]
## @end group
## @end example
## @example
## @group
## z = infsup (1);
## intervaltotext (z)
## @result{} [1]
## @end group
## @end example
## @seealso{@@infsup/intervaltoexact}
## @end deftypemethod
## Author: Oliver Heimlich
## Keywords: interval
## Created: 2014-09-30
function [s, isexact] = intervaltotext (x, format)
if (nargin > 2)
print_usage ();
return
endif
isexact = true ();
if (nargin < 2)
format = "decimal";
endif
s = l = u = cell (size (x.inf));
s(isempty (x)) = "[Empty]";
s(isentire (x)) = "[Entire]";
select = not (isempty (x) | isentire (x));
if (any (select(:)))
[l(select), lexact] = mpfr_to_string_d (-inf, format, x.inf(select));
[u(select), uexact] = mpfr_to_string_d (+inf, format, x.sup(select));
isexact = lexact && uexact;
l(x.inf == 0) = "0"; # no sign for zero
## Normalize case of +-Inf
l(select & x.inf == -inf) = "-Inf";
u(select & x.sup == inf) = "Inf";
## If l is negative, then u shall also carry a sign (not zero)
change_of_sign = select & x.inf < 0 & x.sup > 0;
u(change_of_sign) = strcat ("+", u(change_of_sign));
singleton_string = strcmp (l, u);
s(select & singleton_string) = strcat ("[", ...
l(select & singleton_string), ...
"]");
s(select &
not (singleton_string)) = strcat (...
"[", ...
l(select & not (singleton_string)), ...
{", "}, ...
u(select & not (singleton_string)), ...
"]");
endif
if (isscalar (s))
s = s{1};
endif
endfunction
%!assert (intervaltotext (infsup (1 + eps), "exact decimal"), "[1.0000000000000002220446049250313080847263336181640625]");
%!assert (intervaltotext (infsup (1 + eps), "exact hexadecimal"), "[0x1.0000000000001p+0]");
%!test
%! output_precision (3, 'local');
%! assert (intervaltotext (infsup (pi), "auto"), "[3.14, 3.15]");
%! output_precision (4, 'local');
%! assert (intervaltotext (infsup (pi), "auto"), "[3.141, 3.142]");
%!# from the documentation string
%!assert (intervaltotext (infsup (1 + eps)), "[1.0000000000000002, 1.000000000000001]");
%!assert (intervaltotext (nextout (infsup (1 + eps))), "[1, 1.0000000000000005]");
%!assert (intervaltotext (infsup (1)), "[1]");
%!assert (reshape (intervaltotext (infsup (reshape (1:120, 2, 3, 4, 5))), 1, 120), intervaltotext (infsup (1:120)));
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