function g = netderiv(w, net, x)
%NETDERIV Evaluate derivatives of network outputs by weights generically.
% G = NETDERIV(W, NET, X) takes a weight vector W and a network data
% structure NET, together with the matrix X of input vectors, and
% returns the gradient of the outputs with respect to the weights
% evaluated at W.
% See also
% NETEVFWD, NETOPT
% Copyright (c) Ian T Nabney (1996-2001)
fstr = [net.type, 'deriv'];
net = netunpak(net, w);
g = feval(fstr, net, x);