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scripts/general/bitget.m

changeset 10289: 4b124317dc38
parent:1bf0ce0930be
author: John W. Eaton <jwe@octave.org>
date: Tue Feb 09 20:58:55 2010 -0500 (40 minutes ago)
permissions: -rw-r--r--
description: base_properties::set_children: account for hidden children 
     1## Copyright (C) 2004, 2005, 2006, 2007, 2009 David Bateman

     2##

     3## This file is part of Octave.

     4##

     5## Octave is free software; you can redistribute it and/or modify it

     6## under the terms of the GNU General Public License as published by

     7## the Free Software Foundation; either version 3 of the License, or (at

     8## your option) any later version.

     9##

    10## Octave is distributed in the hope that it will be useful, but

    11## WITHOUT ANY WARRANTY; without even the implied warranty of

    12## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    13## General Public License for more details.

    14##

    15## You should have received a copy of the GNU General Public License

    16## along with Octave; see the file COPYING.  If not, see

    17## <http://www.gnu.org/licenses/>.

    18

    19## -*- texinfo -*-

    20## @deftypefn {Function File} {@var{X} =} bitget (@var{a},@var{n})

    21## Return the status of bit(s) @var{n} of unsigned integers in @var{a}

    22## the lowest significant bit is @var{n} = 1.

    23##

    24## @example

    25## @group

    26## bitget (100, 8:-1:1)

    27## @result{} 0  1  1  0  0  1  0  0 

    28## @end group

    29## @end example

    30## @seealso{bitand, bitor, bitxor, bitset, bitcmp, bitshift, bitmax}

    31## @end deftypefn

    32

    33## Liberally based of the version by Kai Habel from octave-forge

    34

    35function X = bitget (A, n)

    36

    37  if (nargin != 2)

    38    print_usage ();

    39  endif

    40

    41  if (isa (A, "double"))

    42    Amax = log2 (bitmax) + 1;

    43    _conv = @double;

    44  else

    45    if (isa (A, "uint8"))

    46      Amax = 8;

    47      _conv = @uint8;

    48    elseif (isa (A, "uint16"))

    49      Amax = 16;

    50      _conv = @uint16;

    51    elseif (isa (A, "uint32"))

    52      Amax = 32;

    53      _conv = @uint32;

    54    elseif (isa (A, "uint64"))

    55      Amax = 64;

    56      _conv = @uint64;

    57    elseif (isa (A, "int8"))

    58      Amax = 8;

    59      _conv = @int8;

    60    elseif (isa (A, "int16"))

    61      Amax = 16;

    62      _conv = @int16;

    63    elseif (isa (A, "int32"))

    64      Amax = 32;

    65      _conv = @int32;

    66    elseif (isa (A, "int64"))

    67      Amax = 64;

    68      _conv = @int64;

    69    else

    70      error ("invalid class %s", class (A));

    71    endif

    72  endif

    73

    74  m = double (n(:));

    75  if (any (m < 1) || any (m > Amax))

    76    error ("n must be in the range [1,%d]", Amax);

    77  endif

    78

    79  X = bitand (A, bitshift (_conv (1), uint8 (n) - uint8 (1))) != _conv (0);

    80endfunction