miceadds (version 1.5-0)

fast.groupmean: Calculation of Groupwise Descriptive Statistics for Matrices

Description

Calculates some groupwise descriptive statistics

Usage

fast.groupmean(data, group, weights=NULL, extend=FALSE)

fast.groupsum(data, group, weights=NULL, extend=FALSE)

Arguments

data

A numeric data frame

group

A vector of group identifiers

weights

An optional vector of sample weights

extend

Optional logical indicating whether the group means (or sums) should be extended to the original dimensions of the dataset.

Value

• A data frame with groupwise calculated statistics

Examples

#############################################################################
# EXAMPLE 1: Group means data.ma02
#############################################################################

data( data.ma02 )
dat <- data.ma02[[1]] # select first dataset

# group means for read and math
fast.groupmean( dat[ , c("read","math") ] , group=dat$idschool )


# extend group means to original dataset
fast.groupmean( dat[ , c("read","math") ] , group=dat$idschool , extend =TRUE )