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 |
4
|
20 function retval = vander (c) |
|
21 |
2303
|
22 ## usage: vander (c) |
|
23 ## |
|
24 ## Return the Vandermonde matrix whose next to last column is c. |
|
25 ## |
|
26 ## See also: hankel, hadamard, hilb, invhilb, toeplitz |
4
|
27 |
|
28 if (nargin != 1) |
904
|
29 usage ("vander (c)"); |
4
|
30 endif |
|
31 |
|
32 nr = rows (c); |
|
33 nc = columns (c); |
|
34 if (nr == 1 && nc == 1) |
|
35 retval = 1; |
|
36 elseif (nr == 1 || nc == 1) |
|
37 n = length (c); |
|
38 if (n > 0) |
|
39 retval = zeros (n, n); |
|
40 for i = 1:n |
|
41 tmp = c(i); |
|
42 for j = 1:n |
|
43 retval (i, j) = tmp ^ (n - j); |
|
44 endfor |
|
45 endfor |
|
46 endif |
|
47 else |
|
48 error ("vander: argument must be a vector"); |
|
49 endif |
|
50 |
|
51 endfunction |