Extract gls Object Groups

DESCRIPTION:

If present, the grouping factor associated to the correlation structure for the linear model represented by object is extracted.

USAGE:

getGroups(object) 

REQUIRED ARGUMENTS:

object
an object inheriting from class gls, representing a generalized least squares fitted linear model.

VALUE:

if the linear model represented by object incorporates a correlation structure and the corresponding corStruct object has a grouping factor, a vector with the group values is returned; else, NULL is returned.

SEE ALSO:

,

EXAMPLES:

fm1 <- gls(follicles ~ sin(2*pi*Time) + cos(2*pi*Time), Ovary, 
           correlation = corAR1(form = ~ 1 | Mare)) 
getGroups(fm1)