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
boxplots 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
formulamethod, a symbolic specification of the formy ~ gcan be given, indicating the observations in the vectoryare to be grouped according to the levels of the factorg.NAs are allowed in the data.- data
a data.frame (or list) from which the variables in
xshould 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
NAs. 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,axisandtitleto 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,jittergives the amount of jittering applied.- offset
when stacking is used, points are stacked this many line-heights (symbol widths) apart.
- vertical
when vertical is
TRUEthe 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:nwherenis 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)
# }