group_mean_center: Group-mean centering.

In bruceR: Broadly Useful Convenient and Efficient R Functions

Group-mean centering.

Description

Compute group-mean centered variables. Usually used for HLM level-1 predictors.

Usage

group_mean_center(
  data,
  vars = setdiff(names(data), by),
  by,
  std = FALSE,
  add.suffix = "",
  add.group.mean = "_mean"
)

Arguments

data	Data object.
vars	Variable(s) to be centered.
by	Grouping variable.
std	Standardized or not. Default is FALSE.
add.suffix	The suffix of the centered variable(s). Default is "". You may set it to "_c", "_center", etc.
add.group.mean	The suffix of the variable name(s) of group means. Default is "_mean" (see Examples).

Value

A new data object containing the centered variable(s).

See Also

grand_mean_center

Examples

d = data.table(x=1:9, g=rep(1:3, each=3))

d.c = group_mean_center(d, "x", by="g")
d.c

d.c = group_mean_center(d, "x", by="g", add.suffix="_c")
d.c

bruceR documentation built on March 7, 2023, 5:41 p.m.