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1 # Copyright (C) 1993 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 the |
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7 # Free Software Foundation; either version 2, or (at your option) any |
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8 # later version. |
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9 # |
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10 # Octave is distributed in the hope that it will be useful, but WITHOUT |
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11 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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12 # FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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13 # 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, 675 Mass Ave, Cambridge, MA 02139, USA. |
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18 |
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4
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19 function sombrero (n) |
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20 |
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21 # usage: sombrero (n) |
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22 # |
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23 # Draw a `sombrero' in three dimensions using n grid lines. The |
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24 # function plotted is |
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25 # |
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26 # z = sin (x^2 + y^2) / (x^2 + y^2); |
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27 |
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28 if (nargin != 1) |
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29 error ("usage: sombrero (n)"); |
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30 endif |
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31 |
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32 x = y = linspace (-8, 8, n)'; |
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33 [xx, yy] = meshdom (x, y); |
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34 r = sqrt (xx .^ 2 + yy .^ 2) + eps; |
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35 z = sin (r) ./ r; |
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36 |
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37 mesh (x, y, z); |
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38 |
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39 endfunction |
