R geom_point and ggmap
I want to plot a ggmap in R, for example, of Australia and have a layer of data points with markers corresponding to the size specified by the following data: sitename lat lon sitenum Sydney -34 151 1 Melbourne -37 144 4 Adelaide -34 138 7 Here's my code, but it's not working... library(ggmap) map <- get_map(location = 'Australia', zoom = 4) mapPoints <- ggmap(map) + geom_point(aes(x = lon, y = lat, size = sitenum), alpha = .5) You need to pass the points as the data argument to geom_points . If they are in the data.frame pp , then the following will owrk ggmap(map) + geom_point(data = pp, aes