panel.superpose(x, y, subscripts, groups, type = "p", ...)
ARGUMENTS:
x
horizontal coordinates of data points.
y
vertical coordinates of data points.
subscripts
subscripts for original data that describe where
x and
y came from.
groups
a factor or character vector that describes the groups that all the data
points belong to.
groups[subscripts] is the same length as
x and
y and gives
the groups corresponding to the
x and
y values on this panel.
This argument can be specified at the high-level function which calls
panel.superpose (see example below).
type
character string (or vector of such) telling how to plot the
x and
y
values in each group:
"p" for points,
"l" for lines, and
"b" for both.
...
graphical parameters that are passed to
points or
lines. They can be
vectors corresponding to different groups of the data.
By default,
the trellis parameter list
superpose.symbol
controls
character size (
cex),
plotting symbol (
pch),
font (
font),
and color (
col) for points;
the
superpose.line parameters control
line width (
lwd),
line type (
lty),
and color (
col) for lines.
If plotting both points and lines (
type="b")
the
superpose.symbol colors are used.
Note that both
superpose.symbol and
superpose.line give vectors of
values for their graphical parameters.
SIDE EFFECTS:
A scatter plot or connected line plot is drawn a group at a time in the
order specified by the levels of
groups.
The graphical parameters are adjusted for each group.
SEE ALSO:
,
.
EXAMPLES:
n <- length(levels(barley$year))
dotplot(variety ~ yield | site, data = barley, groups = year,
panel = function(x, y, ...) {
dot.line <- trellis.par.get("dot.line")
abline(h = y, lwd = dot.line$lwd, lty = dot.line$lty,
col = dot.line$col)
panel.superpose(x, y, ...)
},
layout = c(1, 6),
aspect = 0.5,
xlab = "Barley Yield (bushels/acre)",
main = "(Superpose Example)",
key = list(y = 1.03,
points = Rows(trellis.par.get("superpose.symbol"), 1:n),
text = list(levels(barley$year)), columns = n))