|
2303
|
1 ### Copyright (C) 1996 John W. Eaton |
|
|
2 ### |
|
|
3 ### This file is part of Octave. |
|
|
4 ### |
|
|
5 ### Octave is free software; you can redistribute it and/or modify it |
|
|
6 ### under the terms of the GNU General Public License as published by |
|
|
7 ### the Free Software Foundation; either version 2, or (at your option) |
|
|
8 ### any later version. |
|
|
9 ### |
|
|
10 ### Octave is distributed in the hope that it will be useful, but |
|
|
11 ### WITHOUT ANY WARRANTY; without even the implied warranty of |
|
|
12 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|
|
13 ### General Public License for more details. |
|
|
14 ### |
|
|
15 ### You should have received a copy of the GNU General Public License |
|
|
16 ### along with Octave; see the file COPYING. If not, write to the Free |
|
|
17 ### Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
|
|
18 ### 02111-1307, USA. |
|
245
|
19 |
|
2311
|
20 ## usage: median (a) |
|
|
21 ## |
|
|
22 ## For vector arguments, return the median of the values. |
|
|
23 ## |
|
|
24 ## For matrix arguments, return a row vector containing the median for |
|
|
25 ## each column. |
|
|
26 ## |
|
|
27 ## See also: std, mean |
|
4
|
28 |
|
2311
|
29 function retval = median (a) |
|
4
|
30 |
|
|
31 if (nargin != 1) |
|
2169
|
32 usage ("median (a)"); |
|
4
|
33 endif |
|
|
34 |
|
|
35 [nr, nc] = size (a); |
|
|
36 s = sort (a); |
|
|
37 if (nr == 1 && nc > 0) |
|
|
38 if (rem (nc, 2) == 0) |
|
|
39 i = nc/2; |
|
|
40 retval = (s (i) + s (i+1)) / 2; |
|
|
41 else |
|
|
42 i = ceil (nc/2); |
|
|
43 retval = s (i); |
|
|
44 endif |
|
|
45 elseif (nr > 0 && nc > 0) |
|
|
46 if (rem (nr, 2) == 0) |
|
|
47 i = nr/2; |
|
|
48 retval = (s (i,:) + s (i+1,:)) / 2; |
|
|
49 else |
|
|
50 i = ceil (nr/2); |
|
|
51 retval = s (i,:); |
|
|
52 endif |
|
|
53 else |
|
|
54 error ("median: invalid matrix argument"); |
|
|
55 endif |
|
|
56 |
|
|
57 endfunction |
