PlotBubble: Draw a Bubble Plot

Description

Draw a bubble plot, defined by a pair of coordinates x, y to place the bubbles, an area definition configuring the dimension and a color vector setting the color of the bubbles. The legitimation to define a new function instead of just using plot(symbols(...)) is the automated calculation of the axis limits, ensuring that all bubbles will be fully visible.

Usage

PlotBubble(x, ...)
# S3 method for default
PlotBubble(x, y, area, col = NA, cex = 1, border = par("fg"),
           xlim = NULL, ylim = NULL, na.rm = FALSE, ...)
# S3 method for formula
PlotBubble(formula, data = parent.frame(), ..., subset, ylab = varnames[response])

Arguments

x, y: the x and y co-ordinates for the centres of the bubbles. They can be specified in any way which is accepted by xy.coords.
area: a vector giving the area of the bubbles.
col: colors for the bubbles, passed to symbol. The default NA (or also NULL) means do not fill, i.e., draw transparent bubbles.
cex: extension factor for the area.
border: the border color fot the bubbles. The default means par("fg"). Use border = NA to omit borders.
xlim, ylim: axes limits.
na.rm: logical, should NAs be omitted? Defaults to FALSE.
formula: a formula of the form lhs ~ rhs where lhs gives the data values and rhs the corresponding groups.
data: an optional matrix or data frame (or similar: see model.frame) containing the variables in the formula formula. By default the variables are taken from environment(formula).
subset: an optional vector specifying a subset of observations to be used.
ylab: the y-label for the plot used in the formula interface.
...: the dots are passed to the plot function.

Author

Andri Signorell <andri@signorell.net>

Details

Argument inches controls the sizes of the symbols. If TRUE (the default), the symbols are scaled so that the largest dimension of any symbol is one inch. If a positive number is given the symbols are scaled to make largest dimension this size in inches (so TRUE and 1 are equivalent). If inches is FALSE, the units are taken to be those of the appropriate axes. This behaviour is the same as in symbols.

Examples

Run this code

PlotBubble(latitude ~ longitude, area=(smoky+1)*2e8,
           col=SetAlpha(1, 0.5), data=d.whisky)


cols <- c("olivedrab1","orange","green","mediumturquoise","mediumorchid2","firebrick1")
PlotBubble(x = state.x77[,"Income"], y = state.x77[,"Life Exp"], cex=.00004,
           area = state.x77[,"Population"], col = cols[state.region], border="grey50",
           panel.first=grid(), xlab="Income", ylab="Life Exp.", las=1
)

BubbleLegend(x = "topright", area = c(20000, 10000, 1000), cex=.00004, frame=NA,
             cols=cols[1:3], labels = c(20000, 10000, 1000), cex.names=0.7)

legend(x="bottomright", fill=cols[1:4], legend=levels(state.region))