R: List of lm objects with a common model

by-lmby {doBy} | R Documentation

## 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, sorenh@math.aau.dk

### 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)

[Package doBy version 4.6.6 Index]