by-lmby {doBy}

List of lm objects with a common model

Description

The data is split into strata according to the levels of the grouping factors and individual lm fits are obtained for each stratum.

Usage

lm_by(data, formula, id = NULL, ...)

lmBy(formula, data, id = NULL, ...)

Arguments

data

A dataframe

formula

A linear model formula object of the form y ~ x1 + ... + xn | g1 + ... + gm. In the formula object, y represents the response, ⁠x1, ..., xn⁠ the covariates, and the grouping factors specifying the partitioning of the data according to which different lm fits should be performed.

id

A formula describing variables from data which are to be available also in the output.

...

Additional arguments passed on to lm().

Value

A list of lm fits.

Author(s)

Søren Højsgaard, [e-mail]

Examples

bb <- lmBy(1 / uptake ~ log(conc) | Treatment, data=CO2)
coef(bb)

fitted(bb)
residuals(bb)

summary(bb)
coef(summary(bb))
coef(summary(bb), simplify=TRUE)