group_demean: Subtract mean values by grouping factor
In sboysel/boysel: A collection of miscellaneous R functions

Description Usage Arguments Value Examples

Subtract mean values by grouping factor. Accepts either two vectors (data and groups) or a data.frame and a formula of the form data ~ groups.

group_demean(...)

## S3 method for class 'numeric'
group_demean(x, groups, digits = getOption("digits"),
  named = FALSE, ...)

## S3 method for class 'formula'
group_demean(f, data, digits = getOption("digits"),
  named = FALSE, ...)

`...`	arguments passed to specific methods.
`x`	a numeric vector.
`groups`	a vector of the same length as `x` that contains a group indicator corresponding to each element of `x`.
`digits`	an integer passed directly to `round`.
`named`	If `TRUE`, the names of the ouput vector are set to the original values of the numeric input data.
`f`	a formula. For use with the `data.frame` `data`. Syntax is `x ~ groups` where `x` is a numeric column of `data` that is grouped by `groups`.
`data`	a `data.frame`.

A vector of the same length as the input data (either x or the input column from the data.frame data) where group means have been subtracted from each element in the input data. Specifically, residuals are reported the ordinary least squares regression lm(x ~ factor(groups)).

# using a numeric vector and corresponding grouping vector
x <- runif(50)
g <- rep(letters[1:5], 10)
group_demean(x, g)
# using a formula and data.frame
group_demean(mpg ~ cyl, mtcars)