Estimates the skewness of a statistic from its empirical influence values.
k3.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 which
components of L
) come from which strata.
Value
The skewness estimate calculated from L
.
References
Davison, A. C. and Hinkley, D. V. (1997)
Bootstrap Methods and Their Application. Cambridge University Press.
Examples
# To estimate the skewness of the ratio of means for the city data.
ratio <- function(d, w) sum(d$x * w)/sum(d$u * w)
k3.linear(empinf(data = city, statistic = ratio))
#> [1] 7.831452e-05