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2303
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1 ### Copyright (C) 1996 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, 59 Temple Place - Suite 330, Boston, MA |
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18 ### 02111-1307, USA. |
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245
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19 |
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2311
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20 ## usage: rot90 (x, k) |
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21 ## |
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22 ## Rotate the matrix x counterclockwise k*90 degrees. |
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23 ## |
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24 ## If the second argument is omitted, k is taken to be 1. |
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25 ## |
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26 ## See also: flipud, fliplr |
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27 |
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2311
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28 function y = rot90 (x, k) |
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29 |
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30 if (nargin < 2) |
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31 k = 1; |
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32 endif |
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33 |
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34 if (imag (k) != 0 || fix (k) != k) |
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35 error ("rot90: k must be an integer"); |
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36 endif |
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37 |
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38 if (nargin == 1 || nargin == 2) |
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39 k = rem (k, 4); |
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40 if (k < 0) |
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41 k = k + 4; |
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42 endif |
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43 if (k == 0) |
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44 y = x; |
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45 elseif (k == 1) |
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46 y = flipud (x'); |
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47 elseif (k == 2) |
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48 y = flipud (fliplr (x)); |
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49 elseif (k == 3) |
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50 y = (flipud (x))'; |
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51 else |
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52 error ("rot90: internal error!"); |
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53 endif |
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54 else |
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904
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55 usage ("rot90 (x [, k])"); |
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56 endif |
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57 |
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58 endfunction |
