| plot.design {graphics} | R Documentation | 
Plot univariate effects of one ore more factors,
typically for a designed experiment as analyzed by aov().
Further, in S this a method of the plot generic function
for design objects.
plot.design(x, y = NULL, fun = mean, data = NULL, ...,
            ylim = NULL, xlab = "Factors", ylab = NULL,
            main = NULL, ask = NULL, xaxt = par("xaxt"),
            axes = TRUE, xtick = FALSE)
x | 
either a data frame containing the design factors and
optionally the response, or a formula or
terms object. | 
y | 
the response, if not given in x. | 
fun | 
a function (or name of one) to be applied to each subset. It must return one number for a numeric (vector) input. | 
data | 
data frame containing the variables referenced by x
when that is formula like. | 
... | 
graphical arguments such as col, see par. | 
ylim | 
range of y values, as in plot.default. | 
xlab | 
x axis label, see title. | 
ylab | 
y axis label with a “smart” default. | 
main | 
main title, see title. | 
ask | 
logical indicating if the user should be asked before a new page is started – in the case of multiple y's. | 
xaxt | 
character giving the type of x axis. | 
axes | 
logical indicating if axes should be drawn. | 
xtick | 
logical indicating if “ticks” (one per factor) should be drawn on the x axis. | 
The supplied function will be called once for each level of each
factor in the design and the plot will show these summary values.  The
levels of a particular factor are shown along a vertical line, and the
overall value of fun() for the response is drawn as a
horizontal line.
This is a new R implementation which will not be completely compatible to the earlier S implementations. This is not a bug but might still change.
A big effort was taken to make this closely compatible to the S
version.  However, col (and fg) specification has
different effects.
Roberto Frisullo and Martin Maechler
Chambers, J. M. and Hastie, T. J. eds (1992) Statistical Models in S. Chapman & Hall, London, the white book, pp. 546–7 (and 163–4).
Freeny, A. E. and Landwehr, J. M. (1990) Displays for data from large designed experiments; Computer Science and Statistics: Proc. 22nd Symp. Interface, 117–126, Springer Verlag.
interaction.plot for a “standard graphic”
of designed experiments.
plot.design(warpbreaks)# automatic for data frame with one numeric var.
Form <- breaks ~ wool + tension
summary(fm1 <- aov(Form, data = warpbreaks))
plot.design(       Form, data = warpbreaks, col = 2)# same as above
## More than one y :
utils::str(esoph)
plot.design(esoph) ## two plots; if interactive you are "ask"ed
## or rather, compare mean and median:
op <- par(mfcol = 1:2)
plot.design(ncases/ncontrols ~ ., data = esoph, ylim = c(0, 0.8))
plot.design(ncases/ncontrols ~ ., data = esoph, ylim = c(0, 0.8),
            fun = median)
par(op)