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annotate main/general/bitset.m @ 0:6b33357c7561 octave-forge

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Initial revision
author pkienzle
date Wed, 10 Oct 2001 19:54:49 +0000
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children 23ab5a2ed477
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1 ## Copyright (C) 2000 Kai Habel
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2 ##
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3 ## This program is free software; you can redistribute it and/or modify
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4 ## it under the terms of the GNU General Public License as published by
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5 ## the Free Software Foundation; either version 2 of the License, or
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6 ## (at your option) any later version.
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7 ##
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8 ## This program is distributed in the hope that it will be useful,
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9 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
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10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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11 ## GNU General Public License for more details.
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12 ##
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13 ## You should have received a copy of the GNU General Public License
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14 ## along with this program; if not, write to the Free Software
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15 ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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16
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17 ## -*- texinfo -*-
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18 ## @deftypefn {Function File} {@var{X} =} bitset (@var{a},@var{n})
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19 ## @deftypefnx {Function File} {@var{X} =} bitset (@var{a},@var{n},@var{v})
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20 ## sets or resets bit(s) @var{N} of unsigned integers in @var{A}.
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21 ## @var{v} = 0 resets and @var{v} = 1 sets the bits.
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22 ## The lowest significant bit is: @var{n} = 1
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23 ##
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24 ## @example
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25 ## dec2bin (bitset(10,1))
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26 ## @result{} 1011
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27 ## @seealso{bitand,bitor,bitxor,bitget,bitcmp,bitshift,bitmax}
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28 ## @end deftypefn
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29
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30 ## Author: Kai Habel <kai.habel@gmx.de>
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31
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32 function X = bitset (A, n, value)
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33
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34 if (nargin < 2 || nargin > 3)
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35 usage ("bitset (A, n, v)");
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36 endif
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37
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38 if (nargin == 2)
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39 value = 1;
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40 endif
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41
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42 if (n < 1 || n > (log2(bitmax) + 1) )
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43 msg = sprintf ("n must be in range [1,%d]",round(log2(bitmax)+1));
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44 error (msg);
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45 endif
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46
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47 if (!is_matrix (A) || is_complex (A))
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48 error ("first argument must be a real value");
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49 else
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50 X = bitand (pow2 (n - 1), value);
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51 Y = bitand (A, bitmax - pow2 (n - 1));
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52 X = bitor (X, Y);
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53 endif
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54
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55 endfunction