wapply: Weighted version of the apply function

Description

A function to perform 'apply' on an matrix of data and corresponding matrix of weights.

Usage

wapply(X, MARGIN, FUN, W = NULL, ...)

Arguments

A matrix of data.

MARGIN

A vector giving the subscripts which the function will be applied over. 1 indicates rows, 2 indicates columns.

FUN

The function to be applied. In the case of functions like + the function name must be quoted.

An optional matrix of weights. When W=NULL, the usual apply function is called.

...

optional arguments to FUN.

Value

If each call to FUN returns a vector of length n, then wapply returns an array of dimension c(n, dim(X)[MARGIN]) if n > 1. If n = 1, wapply returns a vector if MARGIN has length 1 and an array of dimension dim(X)[MARGIN] otherwise. If n = 0, the result has length 0 but not necessarily the "correct" dimension.If the calls to FUN return vectors of different lengths, wapply returns a list of length dim(X)[MARGIN].This function is used in the package multtest to compute weighted versions of test statistics. It is called by the function get.Tn inside the user-level function MTP.

Details

When weights are provided, these are passed to FUN along with the data X. For example, if FUN=meanX, each data value is multiplied by the corresponding weight before the mean is applied.

Examples

Run this code

data<-matrix(rnorm(200),nr=20)
weights<-matrix(rexp(200,rate=0.1),nr=20)
wapply(X=data,MARGIN=1,FUN=mean,W=weights)