|
2313
|
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. |
|
904
|
19 |
|
2311
|
20 ## usage: polyderiv (p) |
|
|
21 ## |
|
|
22 ## Returns the coefficients of the derivative of the polynomial whose |
|
|
23 ## coefficients are given by vector p. |
|
|
24 ## |
|
|
25 ## SEE ALSO: poly, polyinteg, polyreduce, roots, conv, deconv, residue, |
|
|
26 ## filter, polyval, polyvalm |
|
1025
|
27 |
|
2312
|
28 ## Author: Tony Richardson <amr@mpl.ucsd.edu> |
|
|
29 ## Created: June 1994 |
|
|
30 ## Adapted-By: jwe |
|
561
|
31 |
|
2312
|
32 function q = polyderiv (p) |
|
561
|
33 |
|
1025
|
34 if (nargin != 1) |
|
|
35 usage ("polyderiv (vector)"); |
|
561
|
36 endif |
|
|
37 |
|
2716
|
38 if (! is_vector (p)) |
|
1025
|
39 error ("argument must be a vector"); |
|
561
|
40 endif |
|
|
41 |
|
1025
|
42 lp = length (p); |
|
|
43 if (lp == 1) |
|
1596
|
44 q = 0; |
|
561
|
45 return; |
|
|
46 elseif (lp == 0) |
|
1596
|
47 q = []; |
|
561
|
48 return; |
|
|
49 end |
|
|
50 |
|
1596
|
51 q = p (1:(lp-1)) .* [(lp-1):-1:1]; |
|
561
|
52 |
|
|
53 endfunction |
