R: Reconstruct data from a linear model

model.data {rsm} | R Documentation

## 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)

### 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.

### 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.

### Value

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

### Author(s)

Russell V. Lenth

### References

Lenth RV (2009) “Response-Surface Methods in R, Using rsm”, Journal of Statistical Software, 32(7), 1–17. http://www.jstatsoft.org/v32/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)

[Package rsm version 2.9 Index]