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1 ## Copyright (C) 1996, 1997, 2002 John W. Eaton |
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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} {} contour (@var{z}, @var{n}) |
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22 ## @deftypefnx {Function File} {} contour (@var{x}, @var{y}, @var{z}, @var{n}) |
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23 ## Make a contour plot of the three-dimensional surface described by |
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24 ## @var{z}. Someone needs to improve @code{gnuplot}'s contour routines |
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25 ## before this will be very useful. |
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26 ## @seealso{plot, mesh, meshgrid} |
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27 ## @end deftypefn |
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28 |
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29 ## Author: jwe |
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30 |
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31 function contour (x, y, z, n) |
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32 |
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33 ## FIXME -- these plot states should really just be set |
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34 ## temporarily, probably inside an unwind_protect block, but there is |
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35 ## no way to determine their current values. |
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36 |
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37 if (nargin == 1 || nargin == 2) |
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38 z = x; |
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39 if (nargin == 1) |
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40 n = 10; |
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41 else |
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42 n = y; |
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43 endif |
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44 if (ismatrix (z)) |
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45 __gnuplot_raw__ ("set nosurface;\n"); |
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46 __gnuplot_raw__ ("set contour;\n"); |
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47 __gnuplot_raw__ ("set cntrparam bspline;\n"); |
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48 if (isscalar (n)) |
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49 command = sprintf ("set cntrparam levels %d;\n", n); |
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50 elseif (isvector (n)) |
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51 tmp = sprintf ("%f", n(1)); |
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52 for i = 2:length (n) |
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53 tmp = sprintf ("%s, %f", tmp, n(i)); |
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54 endfor |
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55 command = sprintf ("set cntrparam levels discrete %s;\n", tmp); |
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56 else |
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57 error ("contour: levels must be a scalar or vector") ; |
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58 endif |
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59 __gnuplot_raw__ (command); |
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60 __gnuplot_set__ parametric; |
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61 __gnuplot_raw__ ("set view 0, 0, 1, 1;\n"); |
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62 __gnuplot_splot__ z w l 1; |
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63 else |
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64 error ("contour: z of contour (z, levels) must be a matrix"); |
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65 endif |
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66 elseif (nargin == 3 || nargin == 4) |
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67 if (nargin == 3) |
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68 n = 10; |
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69 endif |
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70 if (ismatrix (z)) |
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71 size_msg = ["contour: columns(z) must be the same as length(x) and\n" \ |
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72 "rows(z) must be the same as length(y),\n" \ |
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73 "or x, y, and z must be matrices with the same size"]; |
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74 if (isvector (x) && isvector (y)) |
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75 xlen = length (x); |
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76 ylen = length (y); |
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77 if (xlen == columns (z) && ylen == rows (z)) |
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78 if (rows (x) == 1) |
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79 x = x'; |
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80 endif |
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81 len = 3 * ylen; |
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82 zz = zeros (xlen, len); |
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83 k = 1; |
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84 for i = 1:3:len |
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85 zz(:,i) = x; |
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86 zz(:,i+1) = y(k) * ones (xlen, 1); |
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87 zz(:,i+2) = z(k,:)'; |
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88 k++; |
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89 endfor |
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90 else |
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91 error (size_msg); |
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92 endif |
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93 else |
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94 z_size = size (z); |
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95 if (z_size == size (x) && z_size == size (y)) |
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96 nc = 3*z_size(1); |
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97 zz = zeros (z_size(2), nc); |
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98 zz(:,1:3:nc) = x'; |
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99 zz(:,2:3:nc) = y'; |
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100 zz(:,3:3:nc) = z'; |
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101 else |
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102 error (size_msg); |
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103 endif |
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104 endif |
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105 __gnuplot_raw__ ("set nosurface;\n"); |
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106 __gnuplot_raw__ ("set contour;\n"); |
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107 __gnuplot_raw__ ("set cntrparam bspline;\n"); |
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108 if (isscalar (n)) |
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109 command = sprintf ("set cntrparam levels %d;\n", n); |
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110 elseif (isvector (n)) |
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111 tmp = sprintf ("%f", n(1)); |
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112 for i = 2:length (n) |
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113 tmp = sprintf ("%s, %f", tmp, n(i)); |
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114 endfor |
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115 command = sprintf ("set cntrparam levels discrete %s;\n", tmp); |
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116 else |
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117 error ("contour: levels must be a scalar or vector") ; |
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118 endif |
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119 __gnuplot_raw__ (command); |
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120 __gnuplot_set__ parametric; |
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121 __gnuplot_raw__ ("set view 0, 0, 1, 1;\n"); |
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122 __gnuplot_splot__ zz w l 1; |
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123 else |
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124 error ("contour: x and y must be vectors and z must be a matrix"); |
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125 endif |
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126 else |
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127 usage ("contour (x, y, z, levels) or contour (z, levels)"); |
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128 endif |
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129 |
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130 endfunction |
