ggmap map style repository? Now that CloudMade no longer gives out APIs

Question

I'm not sure if this is the right place to ask this question, but does anybody have suggestions for accessing different map styles that can be used for ggmap? CloudMade no longer gives API keys to accounts which are not 'enterprise accounts'.

From "ggmap: Spatial Visualization with ggplot2" (Kahle and Wickham), they suggest to either use Stamen or Google maps, but I'm looking for a different style than offered by these.

Can anybody suggest a repository of map styles that could be used for ggmap?

Cheers

Answer 1

You can get a simple land - water contrast using the maps package:

Set the boundaries of the map with xlim and ylim.

library(maps)
library(ggplot2)

map <- fortify(map(fill = TRUE, plot = FALSE))

ggplot(data = map, aes(x=long, y=lat, group = group)) +
   geom_polygon(fill = "ivory2") +
   geom_path(colour = "black") +
   coord_cartesian(xlim = c(137, 164), ylim = c(-14, 3.6)) +
   theme(panel.background = element_rect(fill = "#F3FFFF"),
          panel.grid.major = element_blank(),
          panel.grid.minor = element_blank())

The map is a bit clunky, but high resolution maps are available in the mapdata package>

library(mapdata)
map <- fortify(map("worldHires", fill = TRUE, plot = FALSE))

ggplot(data = map, aes(x=long, y=lat, group = group)) +
   geom_polygon(fill = "ivory2") +
   geom_path(colour = "black") +
   coord_cartesian(xlim = c(135, 165), ylim = c(-15, 0)) +  # Papua New Guinea
   theme(panel.background = element_rect(fill = "#F3FFFF"),
          panel.grid.major = element_blank(),
          panel.grid.minor = element_blank())  # Be patient

Or a single country can be selected.

map <- fortify(map("worldHires", fill = TRUE, plot = FALSE))

ggplot(data = subset(map, region == "Papua New Guinea"), aes(x=long, y=lat, group = group)) +
   geom_polygon(fill = "ivory2") +
   geom_path(colour = "black") +
   theme(panel.background = element_rect(fill = "#F3FFFF"),
          panel.grid.major = element_blank(),
          panel.grid.minor = element_blank()) 

Answer 2

Google maps has a little know style feature:

https://developers.google.com/maps/documentation/javascript/styling

As another comment noted, get_map is just a wrapper for get_googlemap, etc. And then get_googlemap is just a wrapper for a series of http calls to get map tiles, so it seems possible to hack up the code from get_googlemap a bit so instead of pointing at the basic google map style, it would grab styled tiles.

I may work on this approach over the next month as I have a need for a similar basemap as requested by OP.