annotate scripts/set/intersection.m @ 2313:5ca126254d15

[project @ 1996-07-11 21:25:22 by jwe]
author jwe
date Thu, 11 Jul 1996 21:25:22 +0000
parents 2b5788792cad
children 949ab8eba8bc
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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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19
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20 ## usage: intersection(a,b)
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21 ##
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22 ## Returns the intersection of sets a and b.
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23 ##
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24 ## See - create_set, union, complement
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25
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26 function y = intersection(a,b)
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27
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28 if (nargin != 2)
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29 usage ("intersection(a,b)");
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30 endif
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31
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32 if(isempty(a) || isempty(b))
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33 y = [];
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34 return;
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35 endif
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36
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37 a = create_set(a);
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38 b = create_set(b);
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39
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40 if(length(a) < length(b))
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41 yindex = 1;
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42 y = zeros(1,length(a));
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43 for index = 1:length(a)
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44 if(any(b == a(index)))
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45 y(yindex++) = a(index);
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46 endif
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47 endfor
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48 else
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49 yindex = 1;
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50 y = zeros(1,length(b));
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51 for index = 1:length(b)
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52 if(any(a == b(index)))
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53 y(yindex++) = b(index);
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54 endif
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55 endfor
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56 endif
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57
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58 y = y(1:(yindex-1));
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59
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60 endfunction