[R-sig-Geo] how to create maps from topojson files and csv data?

[Barry Rowlingson]

On Sat, Dec 21, 2013 at 4:18 AM, Tom Buckley <buckley.tom at gmail.com> wrote:
> Nice to see some kindred spirits out there!
>
> TopoJSON --> SP presents some interesting challenges/questions.
>
> I've been writing some amateurish code to address some of these here:
>
> https://github.com/buckleytom/topojson/
>
> Comments/questions welcome. Sorry for the rough shape its in.

 Yes, it might be nice to have a standard way to store objects with
topology in R, since they take up less memory and its easier to
compute things like adjacency using them. However they must be a bit
slower to draw since you need to reassemble the polygons (at least
when drawing filled polygons) and you still then draw every outline
twice.

 SpatialTopoPolygonsDataFrame anyone? It would be coerceable to a
SpatialPolygonsDataFrame with as(x,"SpatialPolygonsDataFrame") but
also have some specific methods that would take advantage of the
topological structure.

 Subsetting is an interesting problem - unless you keep all the
geometry so the arc numbers don't change, you have to change all the
arc numbers... Hmmm....

Barry


Barry