error message in plot(aov-object) -- repost
Uwe Ligges <ligges at statistik.uni-dortmund.de> writes:
plot.lm() produces the error message, in particular the lines
hii <- lm.influence(x, do.coef = FALSE)$hat
which appears to be 1 in some cases, and
rs <- r.w/(s * sqrt(1 - hii))
(you get a division by zero and the outcome is Inf, hence it's not
possible to scale the plot any more).
I'd call it a bug, but I don't know what the bug really is. I'll think
about it...
If the $hat is 1, then the residual is theoretically zero and you should get 0/0 == NA which would be much less trouble. Apparently, floating poing arithmetic makes it not quite so and you get Inf in some cases. I'd expect that rs[hii==1] <- NA would fix things up, although you might possibly need a fuzz factor (hii > 1-1e-10 or so).
O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907