evir (version 1.7-4)

qplot: Exploratory QQplot for Extreme Value Analysis

Description

Creates a QQplot for threshold data against the exponential distribution or the generalized Pareto distribution.

Usage

qplot(data, xi = 0, trim = NA, threshold = NA, line = TRUE,
    labels = TRUE, …)

Arguments

data

data vector

xi

the xi value of a generalized Pareto distribution

trim

value at which data are to be right-truncated

threshold

value at which data are to be left-truncated

line

whether or not a straight line is to be added

labels

whether or not the axes are to be labelled

…

other graphics parameters

Details

If xi is zero the reference distribution is the exponential; if xi is non-zero the reference distribution is the generalized Pareto with that value of xi. In the case of the exponential, the plot is interpreted as follows. Concave departures from a straight line are a sign of heavy-tailed behaviour. Convex departures show thin-tailed behaviour.

See Also

gpd, meplot

Examples

# NOT RUN {
data(danish)
# }
# NOT RUN {
qplot(danish)
# }
# NOT RUN {
# QQplot of heavy-tailed Danish fire insurance data 
# }