boot (version 1.2-10)

var.linear: Linear Variance Estimate

Description

Estimates the variance of a statistic from its empirical influence values.

Usage

var.linear(L, strata=NULL)

Arguments

L

Vector of the empirical influence values of a statistic. These will usually be calculated by a call to empinf.

strata

A numeric vector or factor specifying which observations (and hence empirical influence values) come from which strata.

Value

• The variance estimate calculated from L.

References

Davison, A. C. and Hinkley, D. V. (1997) Bootstrap Methods and Their Application. Cambridge University Press.

See Also

empinf, linear.approx, k3.linear

Examples

#  To estimate the variance of the ratio of means for the city data.
data(city)
ratio <- function(d,w)
     sum(d$x * w)/sum(d$u * w)
var.linear(empinf(data=city,statistic=ratio))