This is a crosspost from stackoverflow. I know very little about GIS software and am doing all my mapping in R. Apologies in advance if this is too basic question. Let's say I have two shapefiles from different sources but with different attributes. Say, one is for adminstrative boundaries of Texas (
boundaries.shp) and the other is for Texas rivers (
rivers.shp). I also have a third file
towns.csv showing the locations of towns within the state. After reading in the files, I can overplot town locations on the adimistrative boundaries in the
plot(boundaries); points(towns$lon, towns$lat)
But how can I overlay all three? Surely there is an easy way of doing this?