Constructs a quantile-quantile plot against a given reference
distribution.
Usage
QQplot(x, a = 0.5, reference = c("normal", "exp", "student"), ...)
Value
Produces QQ-plot and returns invisibly a list of (x, y) pairs.
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.
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.