Create an Area Plot

Produce a stacked area plot, or add polygons to an existing plot.

# Default S3 method
PlotArea(x, y = NULL, prop = FALSE, add = FALSE, xlab = NULL,
         ylab = NULL, col = NULL, frame.plot = FALSE, ...)

# S3 method for class 'formula'
PlotArea(formula, data, subset, na.action, ...)

Arguments

x

numeric vector of x values, or if y=NULL a numeric vector of y values. Can also be a 1-dimensional table (x values in names, y values in array), matrix or 2-dimensional table (x values in row names and y values in columns), a data frame (x values in first column and y values in subsequent columns), or a time-series object of class ts/mts.

y

numeric vector of y values, or a matrix containing y values in columns.

prop

whether data should be plotted as proportions, so stacked areas equal 1.

add

whether polygons should be added to an existing plot.

xlab

label for x axis.

ylab

label for y axis.

col

fill color of polygon(s). The default is a vector of gray colors.

frame.plot

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

formula

a formula, such as y ~ x or cbind(y1, y2) ~ x, specifying x and y values. A dot on the left-hand side, formula = . ~ x, means all variables except the one specified on the right-hand side.

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. Defaults to getOption("na.action").

...

further arguments are passed to matplot and polygon.

Value

Matrix of cumulative sums that was used for plotting.

Author

Arni Magnusson <thisisarni@gmail.com>

See also

barplot, polygon, areaplot

Examples

# PlotArea with stapled areas
tab <- table( d.pizza$date, d.pizza$driver )
PlotArea(x=as.Date(rownames(tab)), y=tab, xaxt="n", xlab="Date", ylab="Pizzas delivered" )

# add x-axis and some text labels
xrng <- pretty(range(as.Date(rownames(tab))))
axis(side=1, at=xrng, labels=xrng)
text( x=min(d.pizza$date + .5, na.rm=TRUE), y=cumsum(tab[2,])-2.5, label=levels(d.pizza$driver),
  adj=c(0,0.5), col=TextContrastColor(gray.colors(7)))



# formula
PlotArea(Armed.Forces~Year, data=longley)

PlotArea(cbind(Armed.Forces,Unemployed)~Year, data=longley)


# add=TRUE
plot(1940:1970, 500*runif(31), ylim=c(0,500))
PlotArea(Armed.Forces~Year, data=longley, add=TRUE)


# matrix
PlotArea(WorldPhones)

PlotArea(WorldPhones, prop=TRUE, col=rainbow(10))


# table
PlotArea(table(d.pizza$weekday))

PlotArea(table(d.pizza$weekday, d.pizza$driver))


# ts/mts
PlotArea(austres)

PlotArea(Seatbelts[,c("drivers","front","rear")],
         ylab="Killed or seriously injured")
abline(v=1983+1/12, lty=3)