[Rspatial-devel] points2grid

[Edzer Pebesma]

The following case,

require(rgdal)
gr = GridTopology(c(0,0), c(1,1), c(20,20))
griLL = SpatialGrid(gr, proj4string = CRS("+init=epsg:4326"))
griMoll = spTransform(griLL, CRS("+proj=moll +lon_0+x_0+y_0"))
griLL2 = spTransform(griMoll, CRS("+init=epsg:4326"))
gridded(griLL2) = TRUE
Error in if (ret at cells.dim[i]>  nr/2) warning(paste("grid topology may
be corrupt in dimension",  :

noted by Jon Skoien, should now also work with sp in svn.  I added the
check:

            if (ru.difx[1] / ru.difx[2] < tolerance) {
                difx = difx[difx > ru.difx[2] * tolerance]
                ru.difx = range(unique(difx)) # reset
            }

it tries to find e.g. x coordinates along a single column that are
nearly identical, ie the difx contains values VERY close to 0.

One of the tests in fail.R now passes, but I believe it does so for good
reasons.
-- 
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