The following arguments have special meaning within this function.
The common meanings for these and all other arguments are listed separately
under
trellis.args.
ARGUMENTS:
formula
a formula in the form
y ~ x | g1 * g2 * ...
however the given variables
g1,
g2 ,
... may be omitted.
y in
formula will be coerced into a factor or shingle.
x must be numeric.
VALUE:
an object of class
trellis,
which is automatically plotted by
print.trellis.
SEE ALSO:
,
.
EXAMPLES:
piechart(variety ~ yield | year * site, data = barley,
xlab = "Barley Yield (bushels/acre)")