diff scripts/general/bitcmp.m @ 4916:c45f14873b5e

[project @ 2004-07-26 14:35:12 by jwe]
author jwe
date Mon, 26 Jul 2004 14:37:05 +0000
parents
children b22a7a1db0d5
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/general/bitcmp.m	Mon Jul 26 14:37:05 2004 +0000
@@ -0,0 +1,65 @@
+## 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} =} bitcmp (@var{a},@var{k})
+## returns the @var{k}-bit complement of integers in @var{a}. If
+## @var{k} is omitted @code{k = log2(bitmax) + 1} is assumed.
+##
+## @example
+## bitcmp(7,4)
+## @result{} 8
+## dec2bin(11)
+## @result{} 1011
+## dec2bin(bitcmp(11))
+## @result{} 11111111111111111111111111110100
+## @end example
+##
+## @seealso{bitand,bitor,bitxor,bitset,bitget,bitcmp,bitshift,bitmax}
+## @end deftypefn
+
+## Liberally based of the version by Kai Habel from octave-forge
+
+function X = bitcmp (A, n)
+  
+  if (nargin < 1 || nargin > 2)
+    usage ("bitcmp(A,n)");
+  endif
+
+  cname = class(A);
+  if (strcmp (cname, "double"))
+    Bmax = bitmax;
+    Amax = log2 (Bmax) + 1;
+  elseif strcmp("uint",substr(cname,1,4))
+    Bmax = intmax(cname);
+    Amax = eval([cname, " (log2 (double (intmax (cname))) + 1);"]);
+  else
+    Bmax = eval([cname, " (-1);"]);
+    Amax = eval([cname, " (log2 (double (intmax (cname))) + 2);"]);
+  endif
+
+  Aone = eval([ cname, "(1);"]);
+  if (nargin == 2)
+    m = eval([cname, " (n(:));"]);
+    if (any(m < Aone) || any( m > Amax))
+      error ("n must be in the range [1,%d]", Amax);
+    endif
+    X = bitxor(A, bitshift(Bmax, -n));
+  else
+    X = bitxor(A, Bmax);
+  endif
+
+endfunction