Constructs a quantile-quantile plot against a given reference
distribution.
Usage
QQplot(x, a = 0.5, reference = c("normal", "exp", "student"), ...)
Arguments
x
vector, data for QQ-plot.
a
numeric, the offset fraction to be used in
ppoints(); typically in (0, 1).
reference
character, name of reference distribution.
...
ellipsis argument, passed down to quantile function of
reference distribution.
Value
Produces QQ-plot and returns invisibly a list of (x, y) pairs.
Details
Special forms like ParetoQQ plots can also be created via this function. E.g.,
to create a ParetoQQ plot, merely pass log(data) in place of data as the first
parameter and use reference = "exp" as the reference
distribution. The ParetoQQ plot should provide a linear graph when a
log transform of the data is plotted against the exponential distribution.