This help topic is for R version 2.9.0. For the current version of R, try https://stat.ethz.ch/R-manual/R-patched/library/stats/html/weighted.mean.html
weighted.mean {stats}R Documentation

Weighted Arithmetic Mean

Description

Compute a weighted mean of a numeric vector.

Usage

weighted.mean(x, w, na.rm = FALSE)

Arguments

x

a numeric vector containing the values whose mean is to be computed.

w

a vector of weights the same length as x giving the weights to use for each element of x.

na.rm

a logical value indicating whether NA values in x should be stripped before the computation proceeds.

Details

If w is missing then all elements of x are given the same weight.

Missing values in w are not handled.

See Also

mean

Examples

## GPA from Siegel 1994
wt <- c(5,  5,  4,  1)/15
x <- c(3.7,3.3,3.5,2.8)
xm <- weighted.mean(x,wt)

[Package stats version 2.9.0 ]