| B_09_tmd {lattice} | R Documentation |
tmd Creates Tukey Mean-Difference Plots from a trellis object
returned by xyplot, qq or qqmath. The prepanel
and panel functions are used as appropriate. The formula
method for tmd is provided for convenience, and simply calls
tmd on the object created by calling xyplot on that
formula.
tmd(object, ...)
## S3 method for class 'trellis'
tmd(object,
xlab = "mean",
ylab = "difference",
panel,
prepanel,
...)
prepanel.tmd.qqmath(x,
f.value = NULL,
distribution = qnorm,
qtype = 7,
groups = NULL,
subscripts, ...)
panel.tmd.qqmath(x,
f.value = NULL,
distribution = qnorm,
qtype = 7,
groups = NULL,
subscripts, ...,
identifier = "tmd")
panel.tmd.default(x, y, groups = NULL, ...,
identifier = "tmd")
prepanel.tmd.default(x, y, ...)
object |
An object of class |
xlab |
x label |
ylab |
y label |
panel |
panel function to be used. See details below. |
prepanel |
prepanel function. See details below. |
f.value, distribution, qtype |
see |
groups, subscripts |
see |
x, y |
data as passed to panel functions in original call. |
... |
other arguments |
identifier |
A character string that is prepended to the names of grobs that are created by this panel function. |
The Tukey Mean-difference plot is produced by modifying the (x,y)
values of each panel as follows: the new coordinates are given by
x=(x+y)/2 and y=y-x, which are then plotted. The
default panel function(s) add a reference line at y=0 as well.
tmd acts on the a "trellis" object, not on the actual plot
this object would have produced. As such, it only uses the arguments
supplied to the panel function in the original call, and completely
ignores what the original panel function might have done with this
data. tmd uses these panel arguments to set up its own scales
(using its prepanel argument) and display (using
panel). It is thus important to provide suitable prepanel and
panel functions to tmd depending on the original call.
Such functions currently exist for xyplot, qq (the ones
with default in their name) and qqmath, as listed in the
usage section above. These assume the default displays for the
corresponding high-level call. If unspecified, the prepanel and
panel arguments default to suitable choices.
tmd uses the update method for "trellis" objects,
which processes all extra arguments supplied to tmd.
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
tmd(qqmath(~height | voice.part, data = singer))