I'm using R 2.10.1 with the latest version of all packages (updated today).
I'm confused as to why I'm getting a hard singularity in a simple set
of experimental data:
blots
ID Lot Age Conc
1 1 A 3 4.44
2 2 A 3 4.56
3 3 B 41 4.03
4 4 B 41 4.57
5 5 C 229 4.49
6
You have only one Age value in each Lot. Hence the Age is aliased with one
of the
5 degrees of freedom between lots. You can see it in the picture
xyplot(Conc ~ Age|Lot, data=blots, pch=16)
There is no opportunity for a slope within each of the groups.
Rich
[[alternative HTML version
At 08:44 PM 6/20/2010, RICHARD M. HEIBERGER wrote:
You have only one Age value in each Lot. Hence the Age is aliased
with one of the
5 degrees of freedom between lots. You can see it in the picture
xyplot(Conc ~ Age|Lot, data=blots, pch=16)
There is no opportunity for a slope within each of
3 matches
Mail list logo
