Hello Thiago, First, I owe you and the list a reproducible example (my first example does not run properly - my bad):
dat <- data.frame(x=runif(50), y=runif(50), category=sample(letters[1:3], size=50, replace=TRUE), continuous=runif(50)) # You may want to do some spatial analysis on that data.frame library(sp) coordinates(dat) <- ~x+y # Some spatial analysis here # Now you want to plot it library(ggplot2) df <- as.data.frame(dat) # backtransforms dat into a data.frame object (ggplot2 does not handle sp objects) # Here I chose to plot the continuous variable with the size of the bubbles, and the categorical variable with the colours my.plot <- ggplot(data=df, aes(x=x, y=y)) + geom_point(aes(size=continuous, colour=category)) + coord-equal() print(my.plot) Second, about plotting a shape file: yes, it is possible. Consider this blog entry for example: http://blog.revolutionanalytics.com/2009/11/choropleth-challenge-result.html Basically, you want to use either geom_path() for simple state boundaries, or geom_polygon() for polygons (e.g. you want to map some attribute by state). Sorry I haven't much experience with this. That could be a good question on the ggplot2 mailing list (http://groups.google.com/group/ggplot2). Pierre 2010/8/25 Thiago Veloso <thi_vel...@yahoo.com.br>: > Hello, Matthew. > Just a superb complement of yours. > I was about to ask the same question to Pierre and Paul, after thanking > them for the useful and functional tip. I managed to follow the ggplot > examples, but a next step would involve plotting my interest points over a > shape file (state contour). > Is that possible? > Best wishes, > Thiago. > > --- On Tue, 24/8/10, Matthew Landis <lan...@isciences.com> wrote: > > From: Matthew Landis <lan...@isciences.com> > Subject: Re: [R-sig-Geo] Mapping multiple attributes at once > To: r-sig-geo@stat.math.ethz.ch > Date: Tuesday, 24 August, 2010, 11:47 > > I've been following this topic with some interest, since this is something I > might like to do fairly often. I'm not that familiar with ggplot2, but it > looks really useful. Is there a way to overplot (or underplot) a shapefile > (e.g. of coastlines) with the approach suggested by Paul? > > Matt > > On 8/24/2010 10:25 AM, Paul Hiemstra wrote: >> In addition to the reply by Pierre Roudier, take a look at the ggplot2 >> pacakge. An example: >> > > > -- ~~~~~~~~~~~~~~~~~~~~~~~~~~ > Matthew Landis, Ph.D. > Research Scientist > ISciences, LLC > 61 Main St. Suite 200 > Burlington VT 05401 > 802.864.2999 > ~~~~~~~~~~~~~~~~~~~~~~~~~~ > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > > > > [[alternative HTML version deleted]] > > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo