varcomp function.
is.random(object, ...)) is.random(object) <- value
object is random or fixed.
object
.
If
value is shorter than
the number of factors in
object,
then
value is replicated.
The
is.random function is generic with
a method for
"data.frame"
and a method for
"factor".
A factor is random if it is of class
"ranfact"
which inherits from
"factor".
guayule <- guayule # create a local copy of the data frame
is.random(guayule[, c("reps", "flats")]) <- T
is.random(guayule)
rm(guayule)