calc.mean: Calculate the Mean of a Variable for Each Subject

In wviechtb/esmpack: Functions that Facilitate Preparation and Management of ESM/EMA Data

Calculate the Mean of a Variable for Each Subject

Description

Function that calculates the mean of a particular variable for each subject.

Usage

calc.mean(x, id, data, na.rm=TRUE, expand=FALSE)

Arguments

x	argument to specify the variable.
id	argument to specify a subject id variable.
data	optional data frame that contains the variables specified above.
na.rm	logical indicating whether missing values should be removed before computing the means (default is TRUE).
expand	logical indicating whether to expand the returned vector so that it can be added back to the dataset as a new variable (default is FALSE).

Details

The function computes the mean of a particular variable for each subject.

When expand=TRUE, the mean for each subject is repeated in such a way that the returned vector can be added back to the dataset as a new variable. See ‘Examples’.

Value

A vector.

Author(s)

Wolfgang Viechtbauer [e-mail]

See Also

calc.mcent

Examples

# illustrative dataset
dat <- data.frame(subj=rep(1:4, each=5),
                  obs = 1:5,
                  age = rep(c(20,31,27,22), each=5),
                  stress = c(2,3,NA,4,2, 3,3,NA,3,NA, 1,1,2,6,4, 1,2,1,3,1))
dat

# calculate the subject-level means of the stress variable
calc.mean(stress, subj, data=dat)

# add this variable back to the original dataset
dat$mstress <- calc.mean(stress, subj, data=dat, expand=TRUE)
dat

wviechtb/esmpack documentation built on April 12, 2025, 9:48 p.m.