ngrps function

Number of Levels of a Factor or a "merMod" Model

Returns the number of levels of a factor or a set of factors, currently e.g., for each of the grouping factors of lmer(), glmer(), etc.

ngrps(object, ...)

Arguments

• object: an R object, see Details.
• ...: currently ignored.

Returns

The number of levels (of a factor) or vector of number of levels for each grouping factor of a

Details

Currently there are methods for objects of class merMod, i.e., the result of lmer() etc, and factor objects.

Examples

ngrps(factor(seq(1,10,2)))
ngrps(lmer(Reaction ~ 1|Subject, sleepstudy))

## A named vector if there's more than one grouping factor :
ngrps(lmer(strength ~ (1|batch/cask), Pastes))
## cask:batch      batch
##         30         10

methods(ngrps) # -> "factor" and "merMod"