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1 ## Copyright (C) 2004 David BAteman |
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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 ## @end example |
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28 ## |
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29 ## @seealso{bitand,bitor,bitxor,bitget,bitcmp,bitshift,bitmax} |
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30 ## @end deftypefn |
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31 |
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32 ## Liberally based of the version by Kai Habel from octave-forge |
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33 |
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34 function X = bitset (A, n, value) |
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35 if (nargin < 2 || nargin > 3) |
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36 usage ("bitset (A, n, v)"); |
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37 endif |
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38 |
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39 if (nargin == 2) |
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40 value = 1; |
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41 endif |
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42 |
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43 cname = class(A); |
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44 if (strcmp (cname, "double")) |
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45 Bmax = bitmax; |
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46 Amax = log2 (Bmax) + 1; |
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47 elseif strcmp("uint",substr(cname,1,4)) |
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48 Bmax = intmax(cname); |
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49 Amax = eval([cname, " (log2 (double (intmax (cname))) + 1);"]); |
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50 else |
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51 Bmax = eval([cname, " (-1);"]); |
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52 Amax = eval([cname, " (log2 (double (intmax (cname))) + 2);"]); |
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53 endif |
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54 |
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55 Aone = eval([ cname, "(1);"]); |
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56 m = eval([cname, " (n(:));"]); |
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57 if (any(m < Aone) || any( m > Amax)) |
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58 error ("n must be in the range [1,%d]", Amax); |
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59 endif |
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60 |
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61 ## XXX FIXME XXX Need extra cast to cname due to bad return value of .^ |
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62 X = eval (["bitand (A, Bmax - ", cname, " (", cname, " (2) .^ (", cname, " (n) - Aone)));"]); |
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63 |
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64 if (value) |
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65 X = eval (["bitor (A, ", cname, " (2) .^ (", cname, " (n) - Aone));"]); |
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66 endif |
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67 |
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68 endfunction |
