|
2847
|
1 ## Copyright (C) 1996, 1997 John W. Eaton |
|
2313
|
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 |
|
5307
|
17 ## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
|
|
18 ## 02110-1301, USA. |
|
245
|
19 |
|
3372
|
20 ## -*- texinfo -*- |
|
|
21 ## @deftypefn {Function File} {} trace (@var{a}) |
|
|
22 ## Compute the trace of @var{a}, @code{sum (diag (@var{a}))}. |
|
|
23 ## @end deftypefn |
|
4
|
24 |
|
2314
|
25 ## Author: jwe |
|
|
26 |
|
2311
|
27 function y = trace (x) |
|
4
|
28 |
|
|
29 if (nargin != 1) |
|
904
|
30 usage ("trace (x)"); |
|
4
|
31 endif |
|
|
32 |
|
1065
|
33 [nr, nc] = size (x); |
|
|
34 if (nr == 1 || nc == 1) |
|
|
35 y = x(1); |
|
|
36 else |
|
|
37 y = sum (diag (x)); |
|
|
38 endif |
|
4
|
39 |
|
|
40 endfunction |
