rsm (version 2.10.4)

model.data: Reconstruct data from a linear model

Description

Create a data frame with just the variables in the formula in a lm object. This is comparable to model.matrix or model.frame except that factors, polynomials, transformations, etc. are not expanded.

Usage

model.data(lmobj, lhs = FALSE)

Value

A data frame containing each of the variables referenced in the model formula.

Arguments

lmobj

An object returned by lm or one of its relatives.

lhs

Boolean indicator of whether or not to include the variable(s) on the left-hand side of the model formula.

Author

Russell V. Lenth

Details

This is an easy-to-use substitute for get_all_vars. The formula, data, and subset arguments, if present in lmobj's call, affect the result appropriately.

References

Lenth RV (2009) ``Response-Surface Methods in R, Using rsm'', Journal of Statistical Software, 32(7), 1--17. tools:::Rd_expr_doi("10.18637/jss.v032.i07")

See Also

model.matrix, model.frame

Examples

library(rsm)
trees.lm <- lm(log(Volume) ~ poly(log(Girth),3), data = trees, subset = 1:20)
model.frame(trees.lm)
model.data(trees.lm)