Description
Creates a bar plot with vertical or horizontal bars.
Usage
barplot(height, …)# S3 method for defaultbarplot(height, width = 1, space = NULL, names.arg = NULL, legend.text = NULL, beside = FALSE, horiz = FALSE, density = NULL, angle = 45, col = 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, add = FALSE, ann = !add && par("ann"), args.legend = NULL, …)
# S3 method for formulabarplot(formula, data, subset, na.action, horiz = FALSE, xlab = NULL, ylab = NULL, …)
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 a matrix and beside
is FALSE
then each bar of the plot corresponds to a column of height
, with the values in the column giving the heights of stacked sub-bars making up the bar. If height
is a matrix and beside
is TRUE
, then the values in each column are juxtaposed rather than stacked.
width
optional vector of bar widths. Re-cycled to length the number of bars drawn. Specifying a single value will have 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 be specified by two numbers, where the first is the space between bars in the same group, and the second the space between the groups. If not given explicitly, it defaults to c(0,1)
if height
is a matrix and beside
is TRUE
, and to 0.2 otherwise.
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 height
; if legend.text
is true, the row names of height
will be used as labels if they are non-null.
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 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 drawing of shading lines.
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. By default, grey is used if height
is a vector, and a gamma-corrected grey palette if height
is a matrix.
border
the color to be used for the border of the bars. Use border = NA
to omit borders. If there are shading lines, border = TRUE
means use the same colour for the border as for the shading lines.
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?
log
string specifying if axis scales should be logarithmic; see plot.default
.
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 axis names (bar labels).
inside
logical. If TRUE
, the lines which divide adjacent (non-stacked!) bars will be drawn. Only applies when space = 0
(which it partly is when beside = TRUE
).
plot
logical. If FALSE
, nothing is plotted.
axis.lty
the graphics parameter lty
applied to the axis and tick marks of the categorical (default horizontal) axis. Note that by default the axis is suppressed.
offset
a vector indicating how much the bars should be shifted relative to the x axis.
add
logical specifying if bars should be added to an already existing plot; defaults to FALSE
.
ann
logical specifying if the default annotation (main
, sub
, xlab
, ylab
) should appear on the plot, see title
.
args.legend
list of additional arguments to pass to legend()
; names of the list are used as argument names. Only used if legend.text
is supplied.
formula
a formula where the , see the examples.y
variables are numeric data to plot against the categorical x
variables. The formula can have one of three forms: y ~ x y ~ x1 + x2 cbind(y1, y2) ~ x
data
a data frame (or list) from which the variables in formula should be taken.
subset
an optional vector specifying a subset of observations to be used.
na.action
a function which indicates what should happen when the data contain NA
values. The default is to ignore missing values in the given variables.
…
arguments to be passed to/from other methods. For the default method these can include further arguments (such as axes
, asp
and main
) and graphical parameters (see par
) which are passed to plot.window()
, title()
and axis
.
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.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
Murrell, P. (2005) R Graphics. Chapman & Hall/CRC Press.
See Also
plot(…, type = "h")
, dotchart
; hist
for bars of a continuous variable. mosaicplot()
, more sophisticated to visualize several categorical variables.
Examples
# NOT RUN {# Formula methodbarplot(GNP ~ Year, data = longley)barplot(cbind(Employed, Unemployed) ~ Year, data = longley)## 3rd form of formula - 2 categories :op <- par(mfrow = 2:1, mgp = c(3,1,0)/2, mar = .1+c(3,3:1))summary(d.Titanic <- as.data.frame(Titanic))barplot(Freq ~ Class + Survived, data = d.Titanic, subset = Age == "Adult" & Sex == "Male", main = "barplot(Freq ~ Class + Survived, *)", ylab = "# {passengers}", legend = TRUE)# Corresponding table :(xt <- xtabs(Freq ~ Survived + Class + Sex, d.Titanic, subset = Age=="Adult"))# Alternatively, a mosaic plot :mosaicplot(xt[,,"Male"], main = "mosaicplot(Freq ~ Class + Survived, *)", color=TRUE)par(op)# Default methodrequire(grDevices) # for colourstN <- table(Ni <- stats::rpois(100, lambda = 5))r <- barplot(tN, col = rainbow(20))#- type = "h" plotting *is* 'bar'plotlines(r, tN, type = "h", col = "red", lwd = 2)barplot(tN, space = 1.5, axisnames = FALSE, sub = "barplot(..., space= 1.5, axisnames = FALSE)")barplot(VADeaths, plot = FALSE)barplot(VADeaths, plot = FALSE, beside = TRUE)mp <- barplot(VADeaths) # defaulttot <- 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 matricesmtext(side = 1, at = colMeans(mp), line = -2, text = paste("Mean", formatC(colMeans(hh))), col = "red")# Bar shading examplebarplot(VADeaths, angle = 15+10*1:5, density = 20, col = "black", legend = rownames(VADeaths))title(main = list("Death Rates in Virginia", font = 4))# Border colorbarplot(VADeaths, border = "dark blue") # }# NOT RUN {<!-- % lwd = 2 << not passed --># }# NOT RUN {<!-- %notyet barplot(VADeaths, inside = FALSE, main = "barplot(*, inside = FALSE)") --># }# NOT RUN {# Log scales (not much sense here)barplot(tN, col = heat.colors(12), log = "y")barplot(tN, col = gray.colors(20), log = "xy")# Legend locationbarplot(height = cbind(x = c(465, 91) / 465 * 100, y = c(840, 200) / 840 * 100, z = c(37, 17) / 37 * 100), beside = FALSE, width = c(465, 840, 37), col = c(1, 2), legend.text = c("A", "B"), args.legend = list(x = "topleft"))# }
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