Dear R-users:
I have some problems working with lme function, and i would be glad if
anyone could help me.
this kind of analysis i was used to do with PROC MIXED from SAS, but i would
like to move to R, for many reasons...
So, the problem is:
Imagine the I have 3 factors:
fact_A, fact_B and fact_C:
The latter I would assume that is random, and the rest of them are fixed.
Analysing the structure of the random factor, i found that it's necessary to
set up an AR1 model.
in a nutshell, it's a 3-way model, but one of the factors is random.
working in SAS/ proc mixed I the program to analyside this would be:
########################
proc mixed;
class fact_A fact_B fact_C;
model y = fact_A fact_B;
random fact_C /type=AR1;
run;
########################
trying to translate this to R, I tryed after reading ?lme and trying to find
any older message at r-help list.
########
library(nlme)
GD = groupedData(y~1|fact_C, data=DataFrame) # as I see in the help, it's
necessary to covert the data.frame in a groupedData object.
lme(fixed= y~fact_A + fact_B, data=GD, random=~1|fact_+C, corr=corAR1(form=
~1|fact_C)) #and trying to run lme function.
########
Am i doing something wrong (or stupid)? 'cause I am not getting the result
that i wish.
Thanks in advance
Rodrigo.
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