I want to add a legend to my ggmap+geom_point, but I can't make it after multiple tries. Hope to get your help! Thanks.
bbox = c(-22.23, -39.19, 62.29, 38.43)
m = get_stamenmap(bbox = bbox, zoom = 6, maptype = "terrain-background")
points_ar = data.frame(lat = ar$lat, lon = ar$lon)
points_ca = data.frame(lat = ca$lat, lon = ca$lon)
points_eu = data.frame(lat = eu$lat, lon = eu$lon)
ggmap(m) + geom_point(aes(x=lon, y=lat), colour="brown", size = 0.5, data = points_ar)+
geom_point(aes(x=lon, y=lat), colour="orange", size = 0.5, data = points_ca) +
geom_point(aes(x=lon, y=lat), colour="purple", size = 0.5, data = points_eu)