On Mon, Mar 14, 2011 at 9:41 AM, Strategische Analyse CSD Hasselt <csd...@fedpolhasselt.be> wrote: > Hello, > > we want to plot a proportional symbol map with ggplot. Symbols' area should > have the same proportions as the scaled variable. > Hereby an example we found on > http://www.r-bloggers.com/bubble-chart-by-using-ggplot2/ . In this example > we see the proportions of the symbols' area are different from the > proportions of the scaled variable: > > crime <- > read.csv("http://datasets.flowingdata.com/crimeRatesByState2008.csv";, > header=TRUE, sep="\t") > p <- ggplot(crime, aes(murder,burglary,size=population, label=state)) > p <- p+geom_point(colour="red") +scale_area(to=c(1,20))+geom_text(size=3) > > Example: > proportion population Pennsylvania/Tennessee= 2.003 > proportion symbols' area Pennsylvania/Tennessee= +/- 2.50 > > proportion population California/Florida= 2.005 > proportion symbols' area California/Florida= +/-2.25 > > What we would like is that the proportion of the symbols' area is also equal > to 2.0.
To do that you need to make sure the lower limit extends to 0 and the size of the smallest circle is also 0. I think something like scale_area(to=c(0, 20), limits = c(0, 4e7), breaks = 1:4 * 1e7) should suffice. It would also be helpful if you stated how you calculated the areas. Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
