[R-sig-Geo] Rotate SpatialPointsDataFrame and convert to raster

[Julian Burgos]

Dear list,

Hopefully this question will not be too basic.  I have a relatively 
large dataset (~250000 rows) consisting of lat, long and a data value.  
The data has been collected in a regular grid, but the grid is 
"tilted".  In other words, along a row the latitude values increase 
constantly, and along a column the longitude values do the same.  The 
tilt is very slight, but large enough to cause problems when trying to 
convert the SpatialPointsDataFrame object holding the data to a 
SpatialPixels objects.  My ultimate objective is to convert this data to 
a raster file and input it to GRASS.
Any ideas on how to solve this problem?  Is is possible to create raster 
images with a "tilted" grid?
Many thanks,

Julian

-- 

Julian Mariano Burgos
Hafrannsóknastofnunin/Marine Research Institute
Skúlagata 4, 121 Reykjavík, Iceland
Sími/Telephone : +354-5752037
Bréfsími/Telefax:  +354-5752001
Netfang/Email: julian at hafro.is, jmburgos at u.washington.edu