Hi Steffen,
In the parms statement, you can specify parameters for all the variance
components in the model, i.e., the parameters in G as well as in R. You need
to specify them in the same order as they appear in the output (e.g., first
fit your model without parms statement to find out the right order).
I hope this helps you further.
Best regards,
Geert Verbeke
Biostatistical Centre
K.U.Leuven
Kapucijnenvoer 35
B-3000 Leuven
Belgium
Tel: +32 16 33 68 91
Tel (sec): +32 16 33 68 92
Fax: +32 16 33 69 00
Web: http://www.med.kuleuven.ac.be/biostat/
-----Original Message-----
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[mailto:[log in to unmask]]On Behalf Of Steffen Witte
Sent: vrijdag 3 januari 2003 10:48
To: [log in to unmask]
Subject: QUERY: parms-statement
Dear allstaters,
to fit a mixed model Y=Xb+Zu+e in SAS I use the proc mixed procedure. The
G-Matrix is the covariance of the random effects Cov(u) and R-Matrix of the
error term Cov(e).
With the parms statement I can specify values of the covariance parameters.
Does that mean the specification of R? (or specification of
Cov(Y)=ZGZ'+R???)
Thx for help.
Steffen
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Dipl.-Math. Steffen Witte
Universitaet Heidelberg, Abteilung Medizinische Biometrie
Im Neuenheimer Feld 305, D-69120 Heidelberg
T: +49-(0)6221-56-4371, F: +49-(0)6221-56-4195
http://www.biometrie.uni-heidelberg.de
mailto:[log in to unmask]
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