stripchart
1-D Scatter Plots
stripchart
produces one dimensional scatter plots (or dot
plots) of the given data. These plots are a good alternative to
boxplot
s when sample sizes are small.
- Keywords
- hplot
Usage
stripchart(x, …)# S3 method for formula
stripchart(x, data = NULL, dlab = NULL, …,
subset, na.action = NULL)
# S3 method for default
stripchart(x, method = "overplot", jitter = 0.1, offset = 1/3,
vertical = FALSE, group.names, add = FALSE,
at = NULL, xlim = NULL, ylim = NULL,
ylab = NULL, xlab = NULL, dlab = "", glab = "",
log = "", pch = 0, col = par("fg"), cex = par("cex"),
axes = TRUE, frame.plot = axes, …)
Arguments
- x
the data from which the plots are to be produced. In the default method the data can be specified as a single numeric vector, or as list of numeric vectors, each corresponding to a component plot. In the
formula
method, a symbolic specification of the formy ~ g
can be given, indicating the observations in the vectory
are to be grouped according to the levels of the factorg
.NA
s are allowed in the data.- data
a data.frame (or list) from which the variables in
x
should be taken.- subset
an optional vector specifying a subset of observations to be used for plotting.
- na.action
a function which indicates what should happen when the data contain
NA
s. The default is to ignore missing values in either the response or the group.- …
additional parameters passed to the default method, or by it to
plot.window
,points
,axis
andtitle
to control the appearance of the plot.- 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 to1:n
wheren
is the number of boxes.- ylab, xlab
labels: see
title
.- dlab, glab
alternate way to specify axis labels: see ‘Details’.
- xlim, ylim
plot limits: see
plot.window
.- log
on which axes to use a log scale: see
plot.default
- pch, col, cex
Graphical parameters: see
par
.- axes, frame.plot
Axis control: see
plot.default
.
Details
Extensive examples of the use of this kind of plot can be found in Box, Hunter and Hunter or Seber and Wild.
The dlab
and glab
labels may be used instead of xlab
and ylab
if those are not specified. dlab
applies to the
continuous data axis (the X axis unless vertical
is TRUE
),
glab
to the group axis.
Examples
library(graphics)
# NOT RUN {
x <- stats::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\")")
stripchart(decrease ~ treatment,
main = "stripchart(OrchardSprays)",
vertical = TRUE, log = "y", data = OrchardSprays)
stripchart(decrease ~ treatment, at = c(1:8)^2,
main = "stripchart(OrchardSprays)",
vertical = TRUE, log = "y", data = OrchardSprays)
# }