R: Extracting the "Environment" of a Model Formula

model.frame {base}

R Documentation

Extracting the “Environment” of a Model Formula

Description

model.frame (generic function) and its methods return a data.frame with the variables from formula.

Usage

model.frame(formula, data, na.action, ...)
model.frame.default(formula, data=sys.frame(sys.parent()),
                    na.action = na.fail, ...)

Methods for
	lm	glm	aovlist

Arguments

formula

a model formula

data

data.frame or environment where the objects in formula are.

na.action

how NAs are treated.

drop.unused.levels

show factors have unused levels dropped? Defaults to FALSE.

xlev

a named list of character vectors giving the full set of levels to be assumed for each factor.

...

further arguments such as subset and weights. NULL arguments are treated as missing.

Value

A data.frame containing the variables used in formula.

Examples

data(cars)
data.class(model.frame(dist ~ speed, data = cars))