if you can format the code neatly into two vectors x (longitude) and y (latitute), then you could use:
require(ggplot2)
ggplot(data.frame(x = x, y = y, circle_size = '\\add a vector'), aes(x, y, size = circle_size) + geom_point()
I didn't test the above function, but it should produce a very similar plot to the example you provided.