`colDevs`

calculates the column deviations of data values from
a central value (mean, median, etc.), possibly stratified by a grouping variable.

Conceptually, the function is similar to a column-wise `sweep`

,
by group, allowing an arbitrary `center`

function.

`colDevs(x, group, center = mean, ...)`

x

A numeric data frame or matrix.

group

A factor (or variable that can be coerced to a factor) indicating
the membership of each observation in `x`

in one or more groups.
If missing, all the data is treated as a single group.

center

A function used to center the values (for each group if `group`

is specified.
The function must take a vector argument and return a scalar result.

…

Arguments passed down

A numeric matrix containing the deviations from the centering function.

Non-numeric columns of `x`

are removed, with a warning.

`colMeans`

for column means,

# NOT RUN { data(iris) Species <- iris$Species irisdev <- colDevs(iris[,1:4], Species, mean) irisdev <- colDevs(iris[,1:4], Species, median) # trimmed mean, using an anonymous function irisdev <- colDevs(iris[,1:4], Species, function(x) mean(x, trim=0.25)) # no grouping variable: deviations from column grand means # include all variables (but suppress warning for this doc) irisdev <- suppressWarnings( colDevs(iris) ) # }