This function is an S Version 3 generic (see Methods);
method functions can be written to handle specific
S Version 3 classes of data. Classes that already
have methods for this function include
data.frame
,
bdFrame
,
formula
,
lm
,
bdLm
, and
terms
.
formula(object) as.formula(object)
~
operator),
or an object that defines such an expression, such as a fitted model
or a
terms
object.
"formula"
, essentially just the call to
~
.
The
as.formula
function differs only in that it will preserve
the full class attribute of an object that inherits from class
"formula"
.
sqrt(skips) ~ . #or, equivalently formula(sqrt(skips) ~ .) formula(fuel.fit) # find the formula