[R-sig-Geo] as.SpatialPolygons.GridTopology does not return

[Sebastian P. Luque]

Hi,

With the following topology and projection defined:

---<---------------cut here---------------start-------------->---
R> gt.aea
                     X1   X2
cellcentre.offset -1609 -698
cellsize              2    2
cells.dim          1383  892
R> print(gt.aea at cellcentre.offset, digits=12)
[1] -1609.022720303  -698.011235825
R> print(gt.aea at cellsize, digits=12)
[1] 2 2
R> print(gt.aea at cells.dim, digits=12)
[1] 1383  892
R> p4
CRS arguments:
 +proj=aea +units=km +lon_0=214.074 +lat_0=69.641 +lat_1=63.4296666666667 +lat_2=75.8523333333333 +ellps=WGS84 
---<---------------cut here---------------end---------------->---

as.SpatialPolygons.GridTopology(gt.aea, p4), R goes to work using 92-97%
CPU user resource and never returns (well, at least not after 15 min),
which seems abnormal.  sessionInfo():

---<---------------cut here---------------start-------------->---
R> sessionInfo()
R version 2.7.1 (2008-06-23) 
x86_64-pc-linux-gnu 

locale:
LC_CTYPE=en_CA.UTF-8;LC_NUMERIC=C;LC_TIME=en_CA.UTF-8;LC_COLLATE=en_CA.UTF-8;LC_MONETARY=C;LC_MESSAGES=en_CA.UTF-8;LC_PAPER=en_CA.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=en_CA.UTF-8;LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] trip_1.1-1      sp_0.9-26       lattice_0.17-10

loaded via a namespace (and not attached):
[1] grid_2.7.1  tools_2.7.1
---<---------------cut here---------------end---------------->---

Am I running into some floating point issue?  I'd appreciate any
pointers on what the problem might be.  Thanks.


Cheers,

-- 
Seb