Enhanced Bar Plots
Description
An enhancement of the standard barplot() function. Creates a bar plot with vertical or horizontal bars. Can plot confidence intervals for each bar, a lined grid behind the bars, change plot area color and logarithmic axes may be used.
Usage
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15  ## Default S3 method:
barplot2(height, width = 1, space = NULL,
names.arg = NULL, legend.text = NULL, beside = FALSE,
horiz = FALSE, density = NULL, angle = 45,
col = NULL, prcol = NULL, border = par("fg"),
main = NULL, sub = NULL, xlab = NULL, ylab = NULL,
xlim = NULL, ylim = NULL, xpd = TRUE, log = "",
axes = TRUE, axisnames = TRUE,
cex.axis = par("cex.axis"), cex.names = par("cex.axis"),
inside = TRUE, plot = TRUE, axis.lty = 0, offset = 0,
plot.ci = FALSE, ci.l = NULL, ci.u = NULL,
ci.color = "black", ci.lty = "solid", ci.lwd = 1, ci.width = 0.5,
plot.grid = FALSE, grid.inc = NULL,
grid.lty = "dotted", grid.lwd = 1, grid.col = "black",
add = FALSE, panel.first = NULL, panel.last = NULL, ...)

Arguments
height 
either a vector or matrix of values describing the
bars which make up the plot. If 
width 
optional vector of bar widths. Recycled to length the
number of bars drawn. Specifying a single value will no visible
effect unless 
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 
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 
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 
beside 
a logical value. If 
horiz 
a logical value. If 
density 
a vector giving the the density of shading lines, in
lines per inch, for the bars or bar components.
The default value of 
angle 
the slope of shading lines, given as an angle in degrees (counterclockwise), for the bars or bar components. 
col 
a vector of colors for the bars or bar components.
By default, grey is used if 
prcol 
the color to be used for the plot region. 
border 
the color to be used for the border of the bars. 
main, sub 
overall and sub titles 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? 
log 
a character string which contains ‘"x"’ if the x axis is to be logarithmic, ‘"y"’ if the y axis is to be logarithmic and ‘"xy"’ or ‘"yx"’ if both axes are to be logarithmic. 
axes 
logical. If 
axisnames 
logical. If 
cex.axis 
expansion factor for numeric axis labels. 
cex.names 
expansion factor for names. 
inside 
logical. If 
plot 
logical. If 
axis.lty 
the graphics parameter 
offset 
a vector indicating how much the bars should be shifted relative to the x axis. 
plot.ci 
logical. If 
ci.l,ci.u 
The confidence intervals (ci.l = lower bound, ci.u =
upper bound) to be plotted if 
ci.color 
the color for the confidence interval line segments 
ci.lty 
the line type for the confidence interval line segments 
ci.lwd 
the line width for the confidence interval line segments 
ci.width 
length of lines used for the "t" at the end of confidence
interval line segments, as a multple of 
plot.grid 
if 
grid.inc 
the number of grid increments to be plotted 
grid.lty 
the line type for the grid 
grid.lwd 
the line width for the grid 
grid.col 
the line color for the grid 
add 
logical, if 
panel.first 
An expression to be evaluated after the plot region
coordinates have been set up, but prior to the drawing of the bars
and other plot region contents. This can be useful to add additional
plot region content behind the bars. This will also work if

panel.last 
An expression to be evaluated after the bars have been drawn, but prior to the addition of confidence intervals, a legend and the axis annotation 
... 
further graphical parameters ( 
Details
This is a generic function, it currently only has a default method. A formula interface may be added eventually.
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.
Note
Prior to R 1.6.0, barplot
behaved as if axis.lty = 1
,
unintentionally.
0 (zero) and NA values in height
will not be plotted if
using logarithmic scales.
If there are NA values in height
and beside = FALSE
,
values after the NA will not be plotted in stacked bars.
Author(s)
Original barplot() by RCore. Enhancements by Marc Schwartz marc\_schwartz@comcast.net
See Also
plot(..., type = "h")
, dotchart
,
hist
.
Examples
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52  tN < table(Ni < rpois(100, lambda = 5))
r < barplot2(tN, col = 'gray')
# type = "h" plotting *is* `bar'plot
lines(r, tN, type = 'h', col = 'red', lwd = 2)
barplot2(tN, space = 1.5, axisnames = FALSE,
sub = "barplot2(..., space = 1.5, axisnames = FALSE)")
data(VADeaths, package = "datasets")
barplot2(VADeaths, plot = FALSE)
barplot2(VADeaths, plot = FALSE, beside = TRUE)
mp < barplot2(VADeaths) # default
tot < colMeans(VADeaths)
text(mp, tot + 3, format(tot), xpd = TRUE, col = "blue")
barplot2(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)
# Example with confidence intervals and grid
hh < t(VADeaths)[, 5:1]
mybarcol < "gray20"
ci.l < hh * 0.85
ci.u < hh * 1.15
mp < barplot2(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 95 percent error bars", col.sub = mybarcol,
cex.names = 1.5, plot.ci = TRUE, ci.l = ci.l, ci.u = ci.u,
plot.grid = TRUE)
mtext(side = 1, at = colMeans(mp), line = 2,
text = paste("Mean", formatC(colMeans(hh))), col = "red")
box()
# Example with horizontal bars, grid and logarithmic x axis
barplot2(1:10 , log = "x", plot.grid = TRUE, grid.inc = 10,
xlim = c(0.5, 20), horiz = TRUE, cex.axis = 0.9,
prcol = "gray95")
box()
# Bar shading example
barplot2(VADeaths, angle = 15 + 10 * 1:5, density = 20, col = "black",
legend = rownames(VADeaths))
title(main = list("Death Rates in Virginia", font = 4))
# border :
barplot2(VADeaths, border = "dark blue")
