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1 ## Copyright (C) 2003 Shai Ayal |
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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} {} {@var{c} =} contour (@var{x}, @var{y}, @var{z}, @var{vv}) |
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22 ## Compute isolines (countour lines) of the matrix @var{z}. |
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23 ## parameters @var{x}, @var{y} and @var{vn} are optional. |
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24 ## |
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25 ## The return value @var{c} is a 2 by @var{n} matrix containing the |
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26 ## contour lines in the following format |
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27 ## |
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28 ## @example |
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29 ## @var{c} = [lev1, x1, x2, ..., levn, x1, x2, ... |
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30 ## len1, y1, y2, ..., lenn, y1, y2, ...] |
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31 ## @end example |
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32 ## |
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33 ## @noindent |
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34 ## in which contour line @var{n} has a level (height) of @var{levn} and |
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35 ## length of @var{lenn}. |
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36 ## |
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37 ## If @var{x} and @var{y} are omitted they are taken as the row/column |
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38 ## index of @var{z}. @var{vn} is either a scalar denoting the number of |
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39 ## lines to compute or a vector containing the values of the lines. If |
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40 ## only one value is wanted, set @code{@var{vn} = [val, val]}. If |
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41 ## @var{vn} is omitted it defaults to 10. |
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42 ## |
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43 ## @example |
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44 ## levels = linspace (0, 2*pi, 10); |
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45 ## @var{c} = contourc (@var{x}, @var{y}, @var{z}, levels); |
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46 ## @end example |
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47 ## @seealso{contourc, line, plot} |
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48 ## @end deftypefn |
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49 |
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50 ## Author: shaia |
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51 |
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52 function retval = contour (varargin) |
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53 |
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54 [c, lev] = contourc (varargin{:}); |
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55 |
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56 cmap = get (gcf(), "colormap"); |
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57 |
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58 levx = linspace (min (lev), max (lev), size (cmap, 1)); |
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59 |
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60 newplot (); |
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61 |
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62 ## Decode contourc output format. |
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63 i1 = 1; |
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64 while (i1 < length (c)) |
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65 |
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66 clev = c(1,i1); |
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67 clen = c(2,i1); |
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68 |
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69 ccr = interp1 (levx, cmap(:,1), clev); |
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70 ccg = interp1 (levx, cmap(:,2), clev); |
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71 ccb = interp1 (levx, cmap(:,3), clev); |
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72 |
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73 ii = i1+1:i1+clen; |
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74 line (c(1,ii), c(2,ii), "color", [ccr, ccg, ccb]); |
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75 |
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76 i1 += c(2,i1)+1; |
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77 endwhile |
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78 |
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79 if (nargout > 0) |
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80 retval = c; |
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81 endif |
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82 |
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83 endfunction |
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84 |
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85 |
