I read this code last night, and the existing implementation is straightforward, but doesn't handle some of the more complicated things:
sigma restricted encoding (this seems tough - might be worth leaving as a later enhancement) interactions - which lead to: nested designs [partial] factorial designs mixture surface models (i think they're called - regression with interactions) I'm not sure what the ideal spec for a routine building a design matrix is. The existing code does everything you need at a basic level, provided you have all your independent variables, but it doesn't introduce terms to handle interactions. Something on top perhaps needs to take a model spec like A(B) C C*D or whatever and turn that into a set of independent variables for the design matrix routine to handle. I haven't really thought this through yet, but I am hoping to work on it. Ed 2008/6/7 John Darrington <[EMAIL PROTECTED]>: > On Thu, Jun 05, 2008 at 05:05:38PM -0400, Jason Stover wrote: > > The big > problem there is the "accounting" problem of mapping values of a > qualitative > variable back and forth to vectors with binary entries. > > I don't understand why this is a "big" problem, but perhaps I'm being > naive. Would it be possible to have a brief specification for the > problem. > > J' > > -- > PGP Public key ID: 1024D/2DE827B3 > fingerprint = 8797 A26D 0854 2EAB 0285 A290 8A67 719C 2DE8 27B3 > See http://pgp.mit.edu or any PGP keyserver for public key. > > > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > > iD8DBQFISkB+imdxnC3oJ7MRApNtAKCGaZsI7XxsM1a8DSSKGYduhKjbfACfVfPW > MYks5oEKF6xIBucv+mlnT/c= > =WfoS > -----END PGP SIGNATURE----- > > _______________________________________________ > pspp-dev mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/pspp-dev > > _______________________________________________ pspp-dev mailing list [email protected] http://lists.gnu.org/mailman/listinfo/pspp-dev
