Plotting in R on Google Maps

R plot Google Map

### Plotting in R on Google Maps

require(ggmap)
require(data.table)


### 1 ###
# If you have coordinates available, go to 2
# This is a way how to get some coordinates

# Check how many queries you can do
geocodeQueryCheck()

# Some test data
dat <- data.table(address = c("Riga", "Vilnius", "Tallinn",
                              "Valmiera", "Palanga", "Tartu"))

# Geo coding
dat[, c("lat", "lon") := geocode(address), with = F]
dat


### 2 ###
# Ploting on Google Map

# Get a picture
# Change the f to modify the zoom
bbox <- make_bbox(dat[, lat], dat[, lon], f = 1)
map <- get_map(location = bbox, maptype = 'roadmap')


# Plot on picture
ggm1 <- ggmap(map) +
  geom_point(data = dat, aes(lat, lon), colour = "red") +
  ggtitle("BNU workshops")
ggm1