[R-sig-Geo] Spatial data tower of babel

[Virgilio Gómez-Rubio]

Hi,

>  geoR has SpatialPointsDataFrame to geodata - but does it have the
> other way round too? Or is that in sp? It doesn't matter too much,
> since students will find them either way, but does
> as.sp(as.geodata('meuse","zinc")) get you back where you started?

But the problem is that this is not always possible. PPP objects (in
spatstat) store not only the coordinates (and marks) but also the
boundary. So, they are a mix of SpatialPoints and SpatialPolygons...

> That's what students may expect. Conversion is a big headache for new
> users and anything that makes it easier is a plus. Imagine doing
> vignette(spBabel) and getting a whole list of what formats can be
> converted together with caveats and restrictions - sounds good to me.

Yes, that would be handy. 

>  Obviously the problems are in maintainance and keeping conversions up
> to date with any changes in the format in the main package, as well as
> that this package would probably depend on all the other packages...

I am a bit with Edzer regarding a spBabel package. I would prefer to
have all these sp<->other_format in the package that provides the new
classes. The main reason is that the developer of the package will be
responsible for them, so that if any change is made to the S4 classes
the conversion functions will be updated and it will not break
compatibility with other packages/spBabel.

Well, just my two cents...

Virgilio