barplot: Bar Plots

Description

Creates a bar plot with vertical or horizontal bars.

Usage

## S3 method for class 'default':
barplot(height, width = 1, space = NULL,
        names.arg = NULL, legend.text = NULL, beside = FALSE,
        horiz = FALSE, density = NULL, angle = 45,
        col = heat.colors(NR), border = par("fg"),
        main = NULL, sub = NULL, xlab = NULL, ylab = NULL,
        xlim = NULL, ylim = NULL, xpd = TRUE,
        axes = TRUE, axisnames = TRUE,
        cex.axis = par("cex.axis"), cex.names = par("cex.axis"),
        inside = TRUE, plot = TRUE, shift = 0, ...)

Arguments

height

either a vector or matrix of values describing the bars which make up the plot. If height is a vector, the plot consists of a sequence of rectangular bars with heights given by the values in the vector. If height is

width

optional vector of bar widths. Re-cycled to length the number of bars drawn. Specifying a single value will no visible effect unless xlim is specified.

space

the amount of space (as a fraction of the average bar width) left before each bar. May be given as a single number or one number per bar. If height is a matrix and beside is TRUE, space may

names.arg

a vector of names to be plotted below each bar or group of bars. If this argument is omitted, then the names are taken from the names attribute of height if this is a vector, or the column names if it is a matrix.

legend.text

a vector of text used to construct a legend for the plot, or a logical indicating whether a legend should be included. This is only useful when height is a matrix. In that case given legend labels should correspond to the rows of

beside

a logical value. If FALSE, the columns of height are portrayed as stacked bars, and if TRUE the columns are portrayed as juxtaposed bars.

horiz

a logical value. If FALSE, the bars are drawn vertically with the first bar to the left. If TRUE, the bars are drawn horizontally with the first at the bottom.

density

a vector giving the the density of shading lines, in lines per inch, for the bars or bar components. The default value of NULL means that no shading lines are drawn. Non-positive values of density also inhibit the

angle

the slope of shading lines, given as an angle in degrees (counter-clockwise), for the bars or bar components.

col

a vector of colors for the bars or bar components.

border

the color to be used for the border of the bars.

main,sub

overall and sub title for the plot.

xlab

a label for the x axis.

ylab

a label for the y axis.

xlim

limits for the x axis.

ylim

limits for the y axis.

xpd

logical. Should bars be allowed to go outside region?

axes

logical. If TRUE, a vertical (or horizontal, if horiz is true) axis is drawn.

axisnames

logical. If TRUE, and if there are names.arg (see above), the other axis is drawn (with lty=0) and labeled.

cex.axis

expansion factor for numeric axis labels.

cex.names

expansion factor for names.

inside

logical. If TRUE, the lines which divide adjacent bars will be drawn.

plot

logical. If FALSE, nothing is plotted.

shift

a vector indicating how much the bars should be shifted from the x axis.

...

further graphical parameters (par) are passed to plot.window(), title() and

Value

A numeric vector (or matrix, when beside = TRUE), say mp, giving the coordinates of all the bar midpoints drawn, useful for adding to the graph.
If beside is true, use colMeans(mp) for the midpoints of each group of bars, see example.

Details

This is a generic function, it currently only has a default method. A formula interface may be added eventually.

Examples

Run this code

tN <- table(Ni <- rpois(100, lambda=5))
r <- barplot(tN, col='gray')
#- type = "h" plotting *is* `bar'plot
lines(r, tN, type='h', col='red', lwd=2)

barplot(tN, space = 1.5, axisnames=FALSE,
        sub = "barplot(..., space= 1.5, axisnames = FALSE)")

data(VADeaths, package = "base")
barplot(VADeaths, plot = FALSE)
barplot(VADeaths, plot = FALSE, beside = TRUE)

mp <- barplot(VADeaths) # default
tot <- colMeans(VADeaths)
text(mp, tot + 3, format(tot), xpd = TRUE, col = "blue")
barplot(VADeaths, beside = TRUE,
        col = c("lightblue", "mistyrose", "lightcyan",
                "lavender", "cornsilk"),
        legend = rownames(VADeaths), ylim = c(0, 100))
title(main = "Death Rates in Virginia", font.main = 4)

hh <- t(VADeaths)[, 5:1]
mybarcol <- "gray20"
mp <- barplot(hh, beside = TRUE,
        col = c("lightblue", "mistyrose",
                "lightcyan", "lavender"),
        legend = colnames(VADeaths), ylim= c(0,100),
        main = "Death Rates in Virginia", font.main = 4,
        sub = "Faked upper 2*sigma error bars", col.sub = mybarcol,
        cex.names = 1.5)
segments(mp, hh, mp, hh + 2*sqrt(1000*hh/100), col = mybarcol, lwd = 1.5)
stopifnot(dim(mp) == dim(hh))# corresponding matrices
mtext(side = 1, at = colMeans(mp), line = -2,
      text = paste("Mean", formatC(colMeans(hh))), col = "red")

# Bar shading example
barplot(VADeaths, angle = 15+10*1:5, density = 20, col = "black", 
        legend = rownames(VADeaths))
title(main = list("Death Rates in Virginia", font = 4))

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