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1 ## Copyright (C) 2000 Daniel Calvelo |
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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 2, or (at your option) |
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8 ## 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, write to the Free |
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17 ## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
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18 ## 02110-1301, USA. |
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19 |
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20 ## -*- texinfo -*- |
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21 ## @deftypefn {Function File} {} base2dec (@var{s}, @var{b}) |
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22 ## Convert @var{s} from a string of digits of base @var{b} into an |
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23 ## integer. |
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24 ## |
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25 ## @example |
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26 ## base2dec ("11120", 3) |
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27 ## @result{} 123 |
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28 ## @end example |
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29 ## |
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30 ## If @var{s} is a matrix, returns a column vector with one value per |
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31 ## row of @var{s}. If a row contains invalid symbols then the |
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32 ## corresponding value will be NaN. Rows are right-justified before |
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33 ## converting so that trailing spaces are ignored. |
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34 ## |
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35 ## If @var{b} is a string, the characters of @var{b} are used as the |
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36 ## symbols for the digits of @var{s}. Space (' ') may not be used as a |
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37 ## symbol. |
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38 ## |
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39 ## @example |
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40 ## base2dec ("yyyzx", "xyz") |
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41 ## @result{} 123 |
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42 ## @end example |
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43 ## |
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44 ## @end deftypefn |
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45 ## |
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46 ## @seealso{dec2base, dec2bin, bin2dec, hex2dec, dec2hex} |
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47 |
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48 ## Author: Daniel Calvelo <dcalvelo@yahoo.com> |
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49 ## Adapted-by: Paul Kienzle <pkienzle@kienzle.powernet.co.uk> |
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50 |
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51 function out = base2dec (d, base) |
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52 |
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53 if (nargin != 2) |
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54 usage ("n = base2dec('d', base)"); |
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55 endif |
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56 |
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57 symbols = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; |
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58 if (isstr (base)) |
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59 symbols = base; |
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60 base = length (symbols); |
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61 if (any (diff (sort (toascii (symbols))) == 0)) |
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62 error ("base2dec: symbols representing digits must be unique."); |
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63 endif |
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64 elseif (! isscalar (base)) |
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65 error ("base2dec: cannot convert from several bases at once."); |
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66 elseif (base < 2 || base > length (symbols)) |
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67 error ("base2dec: base must be between 2 and 36 or a string of symbols"); |
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68 else |
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69 d = toupper (d); |
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70 endif |
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71 |
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72 ## Right justify the values before anything else. |
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73 d = strjust (d, "right"); |
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74 |
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75 ## Lookup value of symbols in symbol table, with invalid symbols |
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76 ## evaluating to NaN and space evaluating to 0. |
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77 table = NaN * ones (256, 1); |
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78 table (toascii (symbols (1 : base))) = 0 : base-1; |
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79 table (toascii (" ")) = 0; |
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80 d = reshape (table (toascii (d)), size (d)); |
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81 |
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82 ## Multiply the resulting digits by the appropriate power and |
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83 ## sum the rows. |
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84 out = d * (base .^ (columns(d)-1 : -1 : 0)'); |
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85 |
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86 endfunction |
