Slightly off topic, but related :-) [Design Issues]

posted by Shuanghe  – Spain, 2019-12-09 12:00 (243 d 23:55 ago) – Posting: # 20964
Views: 2,801

Hi ElMaestro,

» Note e.g. that the two fits have different residuals and residual df's, which to me means incomplete subjects are not deleted (R does not know and is not being told something is incomplete; the full rank design matrix is still invertible and so on).

What about the following?
X3 <- Xm[-7,]
M3 <- lm(logCmax ~ factor(Seq)+factor(Subj)+factor(Trt)+factor(Per), data=X3)
anova(M3)
lsmeans(M3, "Trt")
confint(pairs(lsmeans(M3, "Trt"), reverse =F), level=0.9)

Xm has missing period (1) for subject 4, X3 has no subject 4. compare anova(M2) and anova(M3), residual and df of residual are same. 90% CI also same. So wouldn't it mean that R deleted the extra period (2) of subject 4 in Xm automatically when doing BE evaluation? Lsmeans are different, so subject 4 period 2 was kept for that calculation. I woulds say that this behaviour is the same as SAS.

All the best,
Shuanghe

Complete thread:

Activity
 Admin contact
20,986 posts in 4,375 threads, 1,460 registered users;
online 17 (1 registered, 16 guests [including 12 identified bots]).
Forum time: Sunday 12:55 CEST (Europe/Vienna)

The interpretation of facts in a certain way
stimulates other scientists’ thoughts.    Róbert Bárány

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5