For anyone interested in working with state space modela via gretl:
please note that we have now replaced the documentation in chapter 30
of the Gretl User's Guide with an account of the new (bundle-style)
interface. We think the new code is now ready to roll, but if anyone
is able to do some testing before the next release -- which should be
in a week or so -- we'd be grateful.
The old Kalman interface is still available for now (but will likely
be removed in the release following the next one). And you can find
the old doc at
http://gretl.sourceforge.net/papers/kalman_old.pdf
Allin Cottrell