Dear R list,
I need some help in extracting comparisons in the result of lme. I have a data
set similar to the example data, Orthodont, using patient subject as a random
effect and did something below:
library(nlme)
library(gregmisc)
data(Orthodont)
Orthodont$AgeGroup <- gtools::quantcut(Orthodont$age)
fm2 <- lme(distance ~ AgeGroup + Sex + AgeGroup*Sex, data = Orthodont, random
= ~1|Subject)
fit.contrast(fm2, "Sex", c(-1,1), conf=0.95)
fit.contrast(fm2, "AgeGroup", rbind("1 vs 2"=c(-1,1,0,0),
"2 vs 3"=c(0,-1,1,0)), conf=0.95)
But how can I compare different age groups among Male, Female or between Male
and Female as illustrated below:
## among Male
Male Female
[1,] -1 0
[2,] 1 0
[3,] 0 0
[4,] 0 0
## among Female
Male Female
[1,] 0 0
[2,] 0 -1
[3,] 0 0
[4,] 0 1
## between Male and Female
Male Female
[1,] -1 0
[2,] 0 0
[3,] 0 0
[4,] 0 1
I'll greatly appreciate it if you may help!
JP Jin Ph.D.
Bioinformatics scientist
Center for Bioinformatics
UNC at Chapel Hill
Chapel Hill, NC
US
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