| stripchart {graphics} | R Documentation |
stripchart produces one dimensional scatter plots (or dot
plots) of the given data. These plots are a good alternative to
boxplots when sample sizes are small.
stripchart(x, method = "overplot", jitter = 0.1, offset = 1/3,
vertical = FALSE, group.names, add = FALSE,
at = NULL, xlim = NULL, ylim = NULL,
main = "", ylab = "", xlab = "",
log = "", pch = 0, col = par("fg"), cex = par("cex"))
x |
the data from which the plots are to be produced. The data
can be specified as a single numeric vector, or as list of numeric
vectors, each corresponding to a component plot. Alternatively a
symbolic specification of the form x ~ g can be given,
indicating the observations in the vector x are to be
grouped according to the levels of the factor g. NAs
are allowed in the data. |
method |
the method to be used to separate coincident points.
The default method "overplot" causes such points to be
overplotted, but it is also possible to specify "jitter" to
jitter the points, or "stack" have coincident points
stacked. The last method only makes sense for very granular data. |
jitter |
when method="jitter" is used, jitter
gives the amount of jittering applied. |
offset |
when stacking is used, points are stacked this many line-heights (symbol widths) apart. |
vertical |
when vertical is TRUE the plots are drawn
vertically rather than the default horizontal. |
group.names |
group labels which will be printed alongside (or underneath) each plot. |
add |
logical, if true add the chart to the current plot. |
at |
numeric vector giving the locations where the charts should
be drawn, particularly when add = TRUE;
defaults to 1:n where n is the number of boxes. |
main, ylab, xlab |
labels: see title. |
xlim, ylim |
plot limits: see plot.window. |
log, pch, col, cex |
Graphical parameters: see par. |
Extensive examples of the use of this kind of plot can be found in Box, Hunter and Hunter or Seber and Wild.
x <- rnorm(50)
xr <- round(x, 1)
stripchart(x) ; m <- mean(par("usr")[1:2])
text(m, 1.04, "stripchart(x, \"overplot\")")
stripchart(xr, method = "stack", add = TRUE, at = 1.2)
text(m, 1.35, "stripchart(round(x,1), \"stack\")")
stripchart(xr, method = "jitter", add = TRUE, at = 0.7)
text(m, 0.85, "stripchart(round(x,1), \"jitter\")")
with(OrchardSprays,
stripchart(decrease ~ treatment,
main = "stripchart(Orchardsprays)", ylab = "decrease",
vertical = TRUE, log = "y"))
with(OrchardSprays,
stripchart(decrease ~ treatment, at = c(1:8)^2,
main = "stripchart(Orchardsprays)", ylab = "decrease",
vertical = TRUE, log = "y"))