Plot with repeated symbols by size

Plots a set of (x,y) data with repeated points denoted by larger symbol sizes

Usage

sizeplot(x, y, scale=1, pow=0.5, powscale=TRUE, size=c(1,4), add=FALSE, ...)

Arguments

x: x coordinates of data
y: y coordinates of data
scale: scaling factor for size of symbols
pow: power exponent for size of symbols
powscale: (logical) use power scaling for symbol size?
size: (numeric vector) min and max size for scaling, if powscale=FALSE
add: (logical) add to an existing plot?
...: other arguments to plot() or points()

Details

Most useful for plotting (e.g.) discrete data, where repeats are likely. If all points are repeated equally, gives a warning. The size of a point is given by \(scale*n^pow\), where n is the number of repeats, if powscale is TRUE, or it is scaled between size[1] and size[2], if powscale is FALSE.

Value

A plot is produced on the current device, or points are added to the current plot if add=TRUE.

Author

Ben Bolker

Examples

 x <- c(0.1,0.1,0.1,0.1,0.1,0.2,0.2,0.2,0.2,0.3,0.3)
 y <- c( 1,  1,  1,  1,  2,  2,  2,  3,  3,  4,  5 )
 plot(x,y)

 sizeplot(x,y)

 sizeplot(x,y,pch=2)