Plot R Data With googleVis

[This article was first published on W. Andrew Barr's Paleoecology Blog, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

Here is a little code snippet that shows how to do two things

  1. Use the Google Maps API to resolve place names into lat-long coordinate pairs.
  2. Plot R dataframes that contain lat-long data (for example from #1) onto Google Maps for quick visualization using the googleVis package.  The embedded map looks a little wonky here but it looks perfectly normal when you plot it locally in your browser. (Note: you need an internet connection for these maps to plot properly). 
Data: plotData • Chart ID: MapID71b85742e7
R version 2.14.1 (2011-12-22) • googleVis-0.2.15Google Terms of UseData Policy
####functions borrwed from
getDocNodeVal=function(doc, path)
   sapply(getNodeSet(doc, path), function(el) xmlValue(el))
  doc = xmlTreeParse(u, useInternal=TRUE)
  str=gsub(' ','%20',str)
  lat=getDocNodeVal(doc, "/GeocodeResponse/result/geometry/location/lat")
  lng=getDocNodeVal(doc, "/GeocodeResponse/result/geometry/location/lng")
  list(lat = lat, lng = lng)
#### End functions borrowed from
# get some names of paleoanthropological sites in France. 
placeNames<-c("Cro Magnon","La Ferrassie","Chauvet Cave","La Chapelle aux Saints", "Le Moustier")
#resolve the placenames into latlong
latLong<-lapply(placeNames, FUN=gGeoCode)
#format the latlong coordinates into the proper format lat:long
#create a dataframe, formatting the place name string first and making the latlong a vector, not list
sites<-gvisMap(plotData,locationvar="latlong",tipvar="name", options=list(mapType='normal'))

To leave a comment for the author, please follow the link and comment on their blog: W. Andrew Barr's Paleoecology Blog. offers daily e-mail updates about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)