[R] lme4--->GLMM
Pavel Khomski
pkhomski at wiwi.uni-bielefeld.de
Thu Feb 17 16:41:48 CET 2005
Hello,
I'm very sorry for my repeated question, which i asked 2 weeks ago, namely:
i'm interested in possibly simple random-part specification in the call
of GLMM(...) (from lme4-package)
i have a random blocked structure (i.e. ~var.a1+var.a2+var.a3,
~var.b1+var.b2,~var.c1+var.c2+var.c3+var.c4),
and each one part of it i would like to model as Identity-structure
matrix. So i had, in symbols of nlme-package,
and for only one cluster-variable my.Subject:
random=list(my.Subject=pdBlocked(list(pdIdent(~var.a1+var.a2+var.a3,...),pdIdent(~var.b1+var.b2,...),pdIdent(~var.c1+var.c2+var.c3+var.c4),...)))
As the lme4-package doesn't use the pdMat-classes for specification of
the random-part in GLMM, i used, with advice of Douglas Bates,
the explicit specification in the GLMM-call (this call can also been
simplified, if i first attach the lme4 package and then the nlme-package):
GLMM(....., random=list(my.Subject=~var.a1+var.a2+var.a3,
my.Subject=~var.b1+var.b2, my.Subject=var.c1+var.c2+var.c3+var.c4),.....)
and really could make estimates in such a way.
The problem is how can i specify a simple matrix sructure for each
block, such as pdIdent(...) in symbols of lme4. is it possible?
Does the lme4 any use of pdMat-specification or something like this? If
not, it seems, that i actually specify a general Covariance Matrix
for each block, what i in principle don't want.
thanks in advance
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