|
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. |
|
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 |
|
2311
|
28 function q = polyderiv (p) |
|
561
|
29 |
|
2303
|
30 ## Written by Tony Richardson (amr@mpl.ucsd.edu) June 1994. |
|
561
|
31 |
|
1025
|
32 if (nargin != 1) |
|
|
33 usage ("polyderiv (vector)"); |
|
561
|
34 endif |
|
|
35 |
|
1025
|
36 if (is_matrix (p)) |
|
|
37 error ("argument must be a vector"); |
|
561
|
38 endif |
|
|
39 |
|
1025
|
40 lp = length (p); |
|
|
41 if (lp == 1) |
|
1596
|
42 q = 0; |
|
561
|
43 return; |
|
|
44 elseif (lp == 0) |
|
1596
|
45 q = []; |
|
561
|
46 return; |
|
|
47 end |
|
|
48 |
|
1596
|
49 q = p (1:(lp-1)) .* [(lp-1):-1:1]; |
|
561
|
50 |
|
|
51 endfunction |
