Stacked Area Plot

Draws one or several stacked area series using cumulative polygons. The function accepts either a matrix of values or separate x and y coordinates. Multiple series are displayed as stacked areas.

Usage

plotArea(
  x,
  y,
  main = NULL,
  xlab = "",
  ylab = "",
  xlim = NULL,
  ylim = NULL,
  prop = FALSE,
  col = NULL,
  grid = .useTheme,
  legend = TRUE,
  stamp = .useTheme,
  ...
)

Arguments

x

numeric vector, matrix or data frame. If y is missing, x is interpreted as a matrix of series where rows correspond to x positions and columns to individual areas.

y

optional numeric vector or matrix giving the y-values. If supplied, x is interpreted as the x-coordinates.

main

main title of the plot.

xlab

label for the x-axis.

ylab

label for the y-axis.

xlim

limits for the x-axis.

ylim

limits for the y-axis.

prop

logical indicating whether rows should be converted to proportions so that stacked areas sum to one.

col

fill colours used for the areas.

grid

controls the background grid. .useTheme (default) follows the active theme (getTheme()$grid), TRUE draws it, FALSE, NULL or NA suppress it, and a named list is passed to graphics::grid().

legend

logical or list controlling the legend. If TRUE, a legend is drawn using the column names of the data. If a list is supplied, its elements are passed to the internal legend drawing routine.

stamp

controls the corner stamp. .useTheme (default) resolves to getTheme()$stamp. TRUE/FALSE/ NULL, a string, or a named list for stamp().

...

additional graphical parameters passed to graphics::par() via .applyParFromDots() and to the plotting functions.

Value

Invisibly returns a list containing:

• x the x-values used for plotting,

• y the original y-values,

• cumulative the cumulative values used to construct the areas,

• legend the legend specification if drawn.

Details

If y is missing, x is interpreted as a matrix and each column is drawn as a separate stacked area.

The cumulative sums are calculated row-wise and displayed as polygons stacked on top of each other.

If prop = TRUE, each row is converted to proportions before plotting, so the stacked areas sum to one.

Row names are used as x-axis labels when available and y is omitted.

See also

Other plot.univariate: plotBar(), plotBox(), plotCatDist(), plotDens(), plotDensBox(), plotDot(), plotECDF(), plotFreqDist(), plotLines(), plotQQ(), plotViolin()

Examples

plotArea(VADeaths)


plotArea(
  WorldPhones,
  col = pal("helsana")
)


plotArea(
  WorldPhones,
  prop = TRUE,
  col = rainbow(ncol(WorldPhones))
)


x <- 1:20
y <- cbind(
  A = runif(20, 1, 5),
  B = runif(20, 1, 3),
  C = runif(20, 1, 4)
)

plotArea(x, y)