qq {lattice} | R Documentation |
Quantile-Quantile plots for comparing two Distributions
qq(formula, ...) ## S3 method for class 'formula': qq(formula, data, f.value = NULL, ...)
formula |
For the formula method, a formula of the form y ~ x | g1 * g2
* ... , where x must be a numeric, and y can be a
factor, shingle, character or numeric vector, with the restriction
that there must be exactly two levels of y , which divide the
values of x into two groups. Quantiles for these groups will
be plotted along the two axes.
|
data |
For the formula methods, an optional data frame in which
variables in the formula (as well as groups and
subset , if any) are to be evaluated. By default, the
environment where the function was called from is used.
|
f.value |
optional function of a single integer (representing
the larger of the two sample sizes), returning a vector of
probabilities corresponding to which quantiles should be
plotted. The typical value for this argument is ppoints ,
which is also the S-PLUS default. If specified, the probabilities
generated by this function is used for the plotted quantiles, using
the quantile function.
f.value defaults to NULL , which is equivalent to
using function(n) ppoints(n, a = 1) . This has the effect of
including the minimum and maximum data values in the computed
quantiles. This is similar to what happens for qqplot but
different from the default qq behaviour in S-PLUS.
|
... |
Other arguments |
qq
produces a Q-Q plot of two samples. The default behaviour
of qq
is different from the corresponding S-PLUS function. See
the entry for f.value
for specifics.
This and all other high level Trellis functions have several
arguments in common. These are extensively documented only in the
help page for xyplot
, which should be consulted to learn more
detailed usage.
An object of class "trellis"
. The
update
method can be used to
update components of the object and the
print
method (usually called by
default) will plot it on an appropriate plotting device.
Deepayan Sarkar Deepayan.Sarkar@R-project.org
xyplot
, panel.qq
,
qqmath
, Lattice
qq(voice.part ~ height, aspect = 1, data = singer, subset = (voice.part == "Bass 2" | voice.part == "Tenor 1"))