pruneLevels(object)
object
|
an object inheriting from class factor .
|
levels
attribute of object
are pruned to contain
only the levels occurring in the factor.object
, but with the levels
attribute containing only value occurring in the factor.factor
, ordered
library(lme) f1 <- factor(c(1,1,2,3,3,4,5)) levels(f1) f2 <- f1[4:7] levels(f2) levels(pruneLevels(f2))