Extracting the ``Environment'' of a Model Formula
Usage
model.frame(formula, data, na.action, ...)
model.frame.default(formula, data=sys.frame(sys.parent()),
na.action = na.fail, ...)
Arguments
formula
|
a model formula
|
data
|
data.frame or environment where the objects
in formula are.
|
na.action
|
how NA s are treated.
|
...
|
further arguments such as.......
|
Description
model.frame
is a generic function, and
model.frame.default
its default method.Value
A data.frame
containing the variables used in
formula
.See Also
model.frame.lm
for the method used in lm
.Examples
data(cars)
data.class(model.frame(dist ~ speed, data = cars))