[R] Nested and repeated effects together?

Stephan Kolassa Stephan.Kolassa at gmx.de
Sun Jun 4 22:10:00 CEST 2006

Dear R people,

I am having a problem with modeling the following SAS code in R:

Class ID Gr Hemi Region Gender
Model Y = Gr Region Hemi Gender Gr*Hemi Gr*Region Hemi*Region 
Gender*Region Gender*Hemi Gr*Hemi*Region Gender*Hemi*Region 
Random Intercept Region Hemi /Subject = ID (Gr Gender)

I.e., ID is a random effect nested in Gr and Gender, leading to 
ID-specific Intercept, Region and Hemi means. We have repeated 
measurements within each ID (one measurement each for the different 
combinations of Hemi and Region, i.e. 2 levels in Hemi: L vs. R; 4 
levels in Region: F vs. C vs. T vs. PO).

I have been trying things like


and do get results, but I am very unsure whether this implements the 
right model. An Error term like

    Error((1+Region+Hemi)/(ID_Vp/(Gender+Gr))), data=daten))

in the above model looks intuitively better to me, but (1) again: I'm 
unsure about this, (2) this crashes my R.

Of course, I have been googling for all permutations of "Nested 
effects", "repeated effects", "random effects" and digging through the 
R-help archives, but I can't seem to locate a similar question having 
been answered before.

Thank you all for your time!

Best regards,

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