Mercurial > octave-nkf
view scripts/general/bitget.m @ 4920:b22a7a1db0d5
[project @ 2004-07-27 18:15:25 by jwe]
author | jwe |
---|---|
date | Tue, 27 Jul 2004 18:16:18 +0000 |
parents | c45f14873b5e |
children | 0896307b1b48 |
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## Copyright (C) 2004 David BAteman ## ## 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 2 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, write to the Free Software ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ## -*- texinfo -*- ## @deftypefn {Function File} {@var{X} =} bitget (@var{a},@var{n}) ## Return the status of bit(s) @var{n} of unsigned integers in @var{a} ## the lowest significant bit is @var{n} = 1. ## ## @example ## bitget (100, 8:-1:1) ## @result{} 0 1 1 0 0 1 0 0 ## @end example ## @seealso{bitand, bitor, bitxor, bitset, bitcmp, bitshift, bitmax} ## @end deftypefn ## Liberally based of the version by Kai Habel from octave-forge function X = bitget (A, n) if (nargin != 2) usage ("bitget (A, n)"); endif cname = class (A); if (strcmp (cname, "double")) Amax = log2 (bitmax) + 1; elseif strcmp ("uint", substr (cname, 1, 4)) Amax = eval ([cname, " (log2 (double (intmax (cname))) + 1);"]); else Amax = eval ([cname, " (log2 (double (intmax (cname))) + 2);"]); endif Aone = eval ([ cname, "(1);"]); m = eval ([cname, " (n(:));"]); if (any (m < Aone) || any (m > Amax)) error ("n must be in the range [1,%d]", Amax); endif X = eval (["bitand (A, ", cname, " (2) .^ (", cname, " (n) - Aone)) != ", cname, "(0);"]); endfunction