[R-sig-Geo] Link to [MetaCRS] Common SQLite-based dictionaries for SRS

[Roger Bivand]

A heads up with regard to a discussion taking place on some lists, started 
on the low-volume MetaCRS list, and reposted elsewhere by Even Roualt:

http://lists.maptools.org/pipermail/proj/2015-August/007196.html

It strikes me that the response by Huw James is very well founded, and 
that the data model for a future common dictionary for coordinate 
reference systems should permit the optional use of historical CRS. This 
is an enduring problem with EPSG codes, which can change with each 
release, so making reproducible research harder (especially as the EPSG 
CSV files in PROJ.4 and GDAL, and versions in the GeoTiff software, do not 
report their versions). I would invite ideas now, to assist in guiding 
MetaCRS towards a robust and time-aware dictionary structure with self 
declaring versioning.

There is a further question of the proposed use of SQLite as the backend, 
as R does not have built-in DB drivers, but has an RSQLite package on 
which future CRS handling might have to depend

Roger

-- 
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 91 00
e-mail: Roger.Bivand at nhh.no