[R-sig-Geo] projection of ggmap:get_map() output

[Agustin Lobo]

I think that the output of get_map commands, i.e.

gmap <- get_map(location = rprobextLL at bbox, maptype = "hybrid", source
= "google",
    crop = FALSE, zoom = 5)

is a raster (not in the sense of an object of the raster package) in
gepgraphic coordinates
(epsg:4326), but actually do not see it specified anywhere. Does
anyone know for sure?
The alternative would be google PseudoMercator (eps:3857)

Also, I'm kind of confused with the get_map help page:
"Value
a data.frame with columns latitude, longitude, and fill"

while in R we get:
> str(gmap)
 chr [1:1280, 1:1280] "#24392B" "#2E4832" "#3E583B" "#3E583B"
"#55675F" "#5B6C52" "#656B58" ...
 - attr(*, "class")= chr [1:2] "ggmap" "raster"
 - attr(*, "bb")='data.frame':    1 obs. of  4 variables:
  ..$ ll.lat: num -38.2
  ..$ ll.lon: num -73.4
  ..$ ur.lat: num -13.2
  ..$ ur.lon: num -45.3


Agus