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1 ## Copyright (C) 2004, 2005, 2006, 2007 David BAteman |
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2 ## |
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3 ## This file is part of Octave. |
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4 ## |
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5 ## Octave is free software; you can redistribute it and/or modify it |
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6 ## under the terms of the GNU General Public License as published by |
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7 ## the Free Software Foundation; either version 3 of the License, or (at |
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8 ## your option) any later version. |
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9 ## |
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10 ## Octave is distributed in the hope that it will be useful, but |
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11 ## WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 ## General Public License for more details. |
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14 ## |
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15 ## You should have received a copy of the GNU General Public License |
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16 ## along with Octave; see the file COPYING. If not, see |
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17 ## <http://www.gnu.org/licenses/>. |
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18 |
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19 ## -*- texinfo -*- |
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20 ## @deftypefn {Function File} {@var{X} =} bitget (@var{a},@var{n}) |
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21 ## Return the status of bit(s) @var{n} of unsigned integers in @var{a} |
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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 ## bitget (100, 8:-1:1) |
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26 ## @result{} 0 1 1 0 0 1 0 0 |
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27 ## @end example |
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28 ## @seealso{bitand, bitor, bitxor, bitset, bitcmp, bitshift, bitmax} |
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29 ## @end deftypefn |
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30 |
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31 ## Liberally based of the version by Kai Habel from octave-forge |
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32 |
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33 function X = bitget (A, n) |
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34 |
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35 if (nargin != 2) |
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36 print_usage (); |
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37 endif |
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38 |
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39 if (isa (A, "double")) |
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40 Amax = log2 (bitmax) + 1; |
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41 _conv = @double; |
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42 else |
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43 if (isa (A, "uint8")) |
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44 Amax = 8; |
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45 _conv = @uint8; |
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46 elseif (isa (A, "uint16")) |
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47 Amax = 16; |
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48 _conv = @uint16; |
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49 elseif (isa (A, "uint32")) |
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50 Amax = 32; |
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51 _conv = @uint32; |
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52 elseif (isa (A, "uint64")) |
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53 Amax = 64; |
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54 _conv = @uint64; |
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55 elseif (isa (A, "int8")) |
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56 Amax = 8; |
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57 _conv = @int8; |
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58 elseif (isa (A, "int16")) |
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59 Amax = 16; |
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60 _conv = @int16; |
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61 elseif (isa (A, "int32")) |
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62 Amax = 32; |
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63 _conv = @int32; |
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64 elseif (isa (A, "int64")) |
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65 Amax = 64; |
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66 _conv = @int64; |
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67 else |
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68 error ("invalid class %s", class (A)); |
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69 endif |
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70 endif |
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71 |
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72 m = double (n(:)); |
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73 if (any (m < 1) || any (m > Amax)) |
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74 error ("n must be in the range [1,%d]", Amax); |
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75 endif |
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76 |
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77 X = bitand (A, bitshift (_conv (1), uint8 (n) - uint8 (1))) != _conv (0); |
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78 endfunction |
