net = mdnunpak(net, w)
net = mdnunpak(net, w) takes an mdn network data structure net and
a weight vector w, and returns a network data structure identical to
the input network, except that the weights in the MLP sub-structure are
set to the corresponding elements of w.
mdn, mdnpak, mdnfwd, mdnerr, mdngradCopyright (c) Christopher M Bishop, Ian T Nabney (1996, 1997)