ggmap.R

library(rgdal)
library(ggplot2)
library(maptools)
library(ggthemes)
# data from http://thematicmapping.org/downloads/TM_WORLD_BORDERS_SIMPL-0.3.zip
gpclibPermit()
world.map <- readOGR(dsn="data/TM_WORLD_BORDERS_SIMPL-0.3/", layer="TM_WORLD_BORDERS_SIMPL-0.3")
world.ggmap <- fortify(world.map, region = "ISO3")
str(world.ggmap)


# sample data 
test  <- data.frame(id = unique(world.ggmap$id))
test$x  <- rnorm(n=nrow(test))

map  <- ggplot(data = test, aes(fill = x)) + 
  geom_map(aes(map_id = id), map =world.ggmap, color = "white") + 
  expand_limits(x = world.ggmap$long, y = world.ggmap$lat) + 
  theme_tufte()

# draw map
png("output/ggmap.png")
map + coord_map()
dev.off()

png("output/ggmap2.png")
map 
dev.off()