ggmap stamen watercolor png error

Question

I would really appreciate some help / ideas about a problem I am having with ggmap and stamen watercolor.

I keep getting the same error message every time I try to cre

Answer 1

I have had the same issue. Note that if you run

get_map(location='Auckland', source="stamen", maptype="watercolor", zoom=13)

you will get the URL(s) for the tiles you're trying to load in R. When I visit one of the URLs given, it redirects to a .jpg, instead of a .png. Hence the error is accurate - the tiles being served are not in PNG format - they're JPGs.

Looks like this is a bug in ggmap introduced by a change in Stamen's API. It appears that version 2.4 will address this; see the GitHub commit here: https://github.com/dkahle/ggmap/commit/c7c48947360351f2e86ba13d0457aa3894b51d46.