qplot function

Exploratory QQplot for Extreme Value Analysis

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

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)
# QQplot of heavy-tailed Danish fire insurance data