mrlplot {extRemes}

Mean Residual Life Plot

Description

An empirical mean residual life plot, including confidence intervals, is produced. The mean residual life plot aids the selection of a threshold for the GPD or point process models.

Usage

mrlplot(x, nint = 100, alpha = 0.05, na.action = na.fail, xlab = "Threshold", ...)

Arguments

x

numeric vector of data.

nint

Number of thresholds to use.

alpha

number giving the 1 - alpha confidence levels to use.

na.action

function to be called to handle missing values.

xlab

character string giving the abscissa label to use.

...

optional arguments to plot.

Details

The mean excesses are found for each value of a range of thresholds that cover the range of the data (less one at the high end). CIs are also shown based on the normal df for the mean excesses. The goal is to find the lowest threshold such that the graph is linear with increasing thresholds, within uncertainty.

See Coles (2001) sec. 4.3.1 for more information.

Value

A matrix with the mean excess values and their confidence bounds is returned invisibly.

Author(s)

Eric Gilleland

References

Coles, S. (2001). An introduction to statistical modeling of extreme values, London, United Kingdom: Springer-Verlag, 208 pp.

See Also

threshrange.plot

Examples

data(Fort)
mrlplot(Fort$Prec)