Extract lmList Object Groups

DESCRIPTION:

The grouping factor determining the partitioning of the observations used to produce the lm components of object is extracted.

USAGE:

getGroups(object) 

REQUIRED ARGUMENTS:

object
an object inheriting from class lmList, representing a list of lm objects with a common model.

VALUE:

a vector with the grouping factor corresponding to the lm components of object.

SEE ALSO:

EXAMPLES:

fm1 <- lmList(distance ~ age | Subject, Orthodont) 
getGroups(fm1)