[R] nested anova
Federico Calboli
f.calboli at ucl.ac.uk
Fri Feb 7 16:57:16 CET 2003
Hi All,
I would like to ask a clarification about a nested anova.
I did an experiment where I check for size differencies in flies. I have:
4 selection lines
3 cage nested in each selection line (12 cages overall)
5 vials nested within each cage (15 vials per line, 60 overall)
I started out with the code:
aov(area ~ selection + cage:selection + vial:cage:selection, scf)
which does not exactly do what I would want (but gives me a fast reading of
the SS I should expect)
The code:
aov(area ~ selection/cage/vial+ Error(selection/cage/vial),scf)
does the trick (althought does not calculate the F value for me)
(BTW, the slighty shorted code
aov(area ~ selection/cage+ Error(selection/cage/vial),scf)
gives the same results).
Now, the question:
assuming that "selection" is a fixed effect and "cage" and "vial" are
random, how do I do the same analysis using lme? I tried to no avail.
Regards,
Federico Calboli
=========================
Federico C.F. Calboli
Department of Biology
University College London
Room 327
Darwin Building
Gower Street
London
WClE 6BT
Tel: (+44) 020 7679 4395
Fax (+44) 020 7679 7096
f.calboli at ucl.ac.uk
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