dotchart {graphics}

Cleveland's Dot Plots

Description

Draw a Cleveland dot plot.

Usage

dotchart(x, labels = NULL, groups = NULL, gdata = NULL, offset = 1/8,
         ann = par("ann"), xaxt = par("xaxt"), frame.plot = TRUE, log = "",
         cex = par("cex"), pt.cex = cex,
         pch = 21, gpch = 21, bg = par("bg"),
         color = par("fg"), gcolor = par("fg"), lcolor = "gray",
         xlim = range(x[is.finite(x)]),
         main = NULL, xlab = NULL, ylab = NULL, ...)

Arguments

x

either a vector or matrix of numeric values (NAs are allowed). If x is a matrix the overall plot consists of juxtaposed dotplots for each row. Inputs which satisfy is.numeric(x) but not is.vector(x) || is.matrix(x) are coerced by as.numeric, with a warning.

labels

a vector of labels for each point. For vectors the default is to use names(x) and for matrices the row labels dimnames(x)[[1]].

groups

an optional factor indicating how the elements of x are grouped. If x is a matrix, groups will default to the columns of x.

gdata

data values for the groups. This is typically a summary such as the median or mean of each group.

offset

offset in inches of ylab and labels.

ann

a logical value indicating whether the default annotation (title and x and y axis labels) should appear on the plot.

xaxt

a string indicating the x-axis style; use "n" to suppress and see also par("xaxt").

frame.plot

a logical indicating whether a box should be drawn around the plot.

log

a character string indicating if one or the other axis should be logarithmic, see plot.default.

cex

the character size to be used. Setting cex to a value smaller than one can be a useful way of avoiding label overlap. Unlike many other graphics functions, this sets the actual size, not a multiple of par("cex").

pt.cex

the cex to be applied to plotting symbols. This behaves like cex in plot().

pch

the plotting character or symbol to be used.

gpch

the plotting character or symbol to be used for group values.

bg

the background color of plotting characters or symbols to be used; use par(bg= *) to set the background color of the whole plot.

color

the color(s) to be used for points and labels.

gcolor

the single color to be used for group labels and values.

lcolor

the color(s) to be used for the horizontal lines.

xlim

horizontal range for the plot, see plot.window, for example.

main

overall title for the plot, see title.

xlab, ylab

axis annotations as in title.

...

graphical parameters can also be specified as arguments.

Value

This function is invoked for its side effect, which is to produce two variants of dotplots as described in Cleveland (1985).

Dot plots are a reasonable substitute for bar plots.

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

Cleveland, W. S. (1985) The Elements of Graphing Data. Monterey, CA: Wadsworth.

Murrell, P. (2005) R Graphics. Chapman & Hall/CRC Press.

Examples

dotchart(VADeaths, main = "Death Rates in Virginia - 1940")

op <- par(xaxs = "i")  # 0 -- 100%
dotchart(t(VADeaths), xlim = c(0,100), bg = "skyblue",
         main = "Death Rates in Virginia - 1940", xlab = "rate [ % ]",
         ylab = "Grouping:  Age  x   Urbanity . Gender")
par(op)