1 ## Copyright (C) 2010 Michel D. Schmid <michaelschmid@users.sourceforge.net>
4 ## This program is free software; you can redistribute it and/or modify it
5 ## under the terms of the GNU General Public License as published by
6 ## the Free Software Foundation; either version 2, or (at your option)
9 ## This program is distributed in the hope that it will be useful, but
10 ## WITHOUT ANY WARRANTY; without even the implied warranty of
11 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 ## General Public License for more details.
14 ## You should have received a copy of the GNU General Public License
15 ## along with this program; see the file COPYING. If not, see
16 ## <http://www.gnu.org/licenses/>.
19 ## @deftypefn {Function File} {} __dradbas (@var{n})
20 ## First derivative of the radial basis transfer function.
22 ## @code{__dradbas(n) = exp(-n^2)*-2*x}
26 ## Author: Michel D. Schmid
29 function retval = __dradbas (n)
34 retval = exp (-n^2)*(-2)*x;
35 # the derivative of exp(-n^2) must be calculated
36 # with help of the chain-rule!
39 # now calculate the product of both
44 #%!assert (radbas (3), exp (-3^2));