.\" -*- nroff -*- generated from .Rd format
.BG
.FN getStrataFormula
.TL
Extract Stratification Formula
.DN
This function is generic; method functions can be written to handle
specific classes of objects. Classes which already have methods for
this function include: `corStruct', `pdMat' and
`reStruct'.
.CS
getStrataFormula(object, ...)
.RA
.AG object
any object from which a formula representing a
stratification variable can be extracted.
.AG ...
some methods for this generic function may require additional
arguments.
.RT
a one-sided formula with the stratification variable associated with
`object'. For most methods, if no stratification
variable is present, a `NULL' value is returned.

.SA
`corStrat', `pdStrat'
.EX
pd1 <- pdStrat(~age, data = Orthodont, strata = ~ Sex)
getStrataFormula(pd1)
.KW models
.WR
