Freedom for replicate bears [🇷 for BE/BA]

posted by ElMaestro  – Denmark, 2011-01-27 22:50 (5620 d 09:57 ago) – Posting: # 6502
Views: 71,958

Dear dlabes and others,

❝ After reading again tons of Websites (seems nobody evaluates x-over studies with R) I came up with the following attempt in R:

❝   model2 <- lme(y~ drug + prd + seq,

❝        random= ~ tmt-1|subj,

❝        #different within variabilities

❝        weights=varIdent(form = ~ 1 | drug),

❝        data=BlaBla, method="REML")


I am starting to believe lme does in some cases not really reach the goal, so I switched to lmer (package lme4). Syntactically something like:
ElModel=lmer(logCmax ~ per+seq+trt + (trt-1|subj))

-which achieves the same.
It will occasionally -depending on the dataset- actually fit the data better (that is, to a higher likelihood and thus with better sigma estimates) than lme can.

And also:
Who's got a 3-period dataset (ref. replicated, but not test-replicated) with a known sWR that I can look at?

Mucho gracias
—
Pass or fail!
ElMaestro

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