[Rspatial-devel] sp: SpatialGrid now directly inherits from Spatial (only)

[Edzer Pebesma]

I committed a largish edit to sp today.

In particular, following my investigations reported here:
https://stat.ethz.ch/pipermail/r-devel/2011-September/062037.html
having SpatialGrid directly inheriting from SpatialPixels does not work,
as it needs an explicit coerce (coordinates are not there!), and setting
this coerce with setAs() does lead to unexpected results (essentially,
objects becoming "Spatial").

Now, SpatialGrid inherits from Spatial, and an explicit setIs() makes it
SpatialPixels too, and sets the right coerce function.

The following methods were moved from functions to S4 generics:
proj4string, proj4string<-, gridded, gridded<-, is.projected.
-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de
http://www.52north.org/geostatistics      e.pebesma at wwu.de