Description
Usage
Arguments
Details
Author(s)
See Also
Examples
panel.xy
is used like panel.xyplot
but offers more
features. In particular, it can add an lqs
resistant regression
line besides a normal one, can plot a prediction interval around the
standard regression line, can add text indicating correlation and
number of data points, and automatically uses different colors and
line styles.
 (x, y, = "p,r,r.pred,r=,N=,grid",
r.min = 0.5, level = 0.8, unicolor = , )

x 
Vector of x coordindates for the plot.

y 
Vector of x coordindates for the plot. Pairs (x,y) containing
NAs will be filtered out.

type 
A character vector (or single commaseparated string) of options to
use for plotting.
Entries "p", "l", "b", "o", "h", "s", "S" are handled just as
plot or panel.xyplot would
(namely as points, lines, both, both overplotted,
histogram lines, stair steps, stair steps with vertical preference).
"g" adds a coordinate grid via panel.grid .
"r" adds an lm regression line. See r.min and
unicolor for details.
The line is suppressed if there are less than 8 points.
"r.pred" adds a prediction interval around the "r"
line. Implies "r" . See level for details.
"r.conf" adds a confidence interval around the "r"
line. This concerns the regression line itself rather than the
predictions it makes and is not often of much interest. Implies
"r" .
level applies just like it does for "r.pred" .
"lqs" adds an lqs resistant regression line.
Roughly speaking, this produces approximately the best regression line
that is possible if it is allowed to throw the most difficult 50% of
the points away. The line is suppressed if there are less than 8 points.
"smooth", "loess", "lowess" are all synonymous and add a
locally weighted regression via panel.loess , whose
configuration parameters will be passed to the call if given.
The line is suppressed if there are less than 8 points.
"ab" adds an arbitrary line (described by parameters a=
and b= ) via panel.ab . This does currently not work due
to parameter name clashes.
"rug" adds a rug plot via panel.rug .
"cor" prints the correlation coefficient computed by
cor in the lower right corner of the plot.
"N" prints the number of nonNA data points in the lower right
corner of the plot.
"v" (verbose) prints various statistics regarding the plot to
the console.

r.min 
Even if type "r" is requested, the regression line
will appear only if abs(cor(x,y) >= r.min) .

level 
The confidence level of the intervals plotted by type "r.conf"
and type "r.pred" .

unicolor 
The colors used for the lines drawn by
types "r", "r.pred", "r.conf", "loess" are normally taken from
trellis.par.get("regression.line")
(as introduced by a.resetplotparams ).
However, if you use xyplot with
panel=panel.superpose, panel.groups=panel.xy , you must specify
unicolor=T . The regression lines will then be plotted in the
style given by trellis.par.get("superpose.line") according to
the respective group.

... 
Further parameters as needed for instance by
panel.loess and lqs .

The types "p", "l", "b", "o", "h", "s", "S"
are in fact
processed by panel.xyplot
.
Specifying col, lty, lwd
will not work, as there are calls that
include both ...
and some of these.
Lutz Prechelt, prechelt@inf.fuberlin.de
a.resetplotparams
,
trellis.par.get
,
panel.xyplot
,
panel.superpose
,
panel.loess
,
lm
,
lqs
.
 # set grid.prompt(TRUE) to see each plot separately (click graphics window)
()
()
(xyplot(Sepal.Width ~ Sepal.LengthSpecies, =,
panel=, ="p,grid,v,lqs,r.pred,loess"))
(xyplot(Sepal.Width ~ Sepal.Length, =, groups=Species,
panel=panel.superpose, panel.groups=,
=("p","grid","v","loess"), unicolor=))

prechelt/agsemisc documentation built on May 25, 2019, 11:26 a.m.