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4916
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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., 51 Franklin Street, Fifth Floor, Boston, MA |
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16 ## 02110-1301 USA |
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4916
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17 |
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18 ## -*- texinfo -*- |
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4920
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19 ## @deftypefn {Function File} {@var{x} =} bitset (@var{a}, @var{n}) |
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20 ## @deftypefnx {Function File} {@var{x} =} bitset (@var{a}, @var{n}, @var{v}) |
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21 ## Set or reset bit(s) @var{n} of unsigned integers in @var{a}. |
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22 ## @var{v} = 0 resets and @var{v} = 1 sets the bits. |
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23 ## The lowest significant bit is: @var{n} = 1 |
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24 ## |
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25 ## @example |
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4920
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26 ## dec2bin (bitset (10, 1)) |
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4916
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27 ## @result{} 1011 |
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28 ## @end example |
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5642
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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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4920
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35 |
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4916
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36 if (nargin < 2 || nargin > 3) |
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37 usage ("bitset (A, n, v)"); |
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38 endif |
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39 |
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40 if (nargin == 2) |
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41 value = 1; |
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42 endif |
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43 |
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4950
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44 if (isa (A, "double")) |
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4916
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45 Bmax = bitmax; |
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46 Amax = log2 (Bmax) + 1; |
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4950
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47 _conv = @double; |
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4916
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48 else |
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4950
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49 if (isa (A, "uint8")) |
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50 Amax = 8; |
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51 _conv = @uint8; |
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52 elseif (isa (A, "uint16")) |
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53 Amax = 16; |
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54 _conv = @uint16; |
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55 elseif (isa (A, "uint32")) |
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56 Amax = 32; |
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57 _conv = @uint32; |
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58 elseif (isa (A, "uint64")) |
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59 Amax = 64; |
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60 _conv = @uint64; |
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61 elseif (isa (A, "int8")) |
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62 Amax = 8; |
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63 _conv = @int8; |
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64 elseif (isa (A, "int16")) |
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65 Amax = 16; |
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66 _conv = @int16; |
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67 elseif (isa (A, "int32")) |
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68 Amax = 32; |
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69 _conv = @int32; |
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70 elseif (isa (A, "int64")) |
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71 Amax = 64; |
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72 _conv = @int64; |
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73 else |
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74 error ("invalid class %s", class (A)); |
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75 endif |
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76 Bmax = intmax (class (A)); |
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4916
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77 endif |
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78 |
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4950
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79 m = double (n(:)); |
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80 if (any (m < 1) || any (m > Amax)) |
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81 error ("n must be in the range [1,%d]", Amax); |
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82 endif |
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83 |
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84 mask = bitshift (_conv (1), uint8 (n) - uint8 (1)); |
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85 X = bitxor (A, bitand (A, mask)); |
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86 |
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87 if (value) |
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88 X = bitor (A, mask); |
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89 endif |
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90 |
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91 endfunction |
