Categorical bubble plot for mapping studies

Question

How to create a categorical bubble plot, using GNU R, similar to that used in systematic mapping studies (see below)?

Answer 1

Here is ggplot2 solution. First, added radius as new variable to your data frame.

grid$radius <- sqrt( grid$count / pi )

You should play around with size of the points and text labels inside the plot to perfect fit.

library(ggplot2)
ggplot(grid,aes(Var1,Var2))+
  geom_point(aes(size=radius*7.5),shape=21,fill="white")+
  geom_text(aes(label=count),size=4)+
  scale_size_identity()+
  theme(panel.grid.major=element_line(linetype=2,color="black"),
        axis.text.x=element_text(angle=90,hjust=1,vjust=0))