GrassHoppers,
I am having a problem with raster cell data. I understand that
Grass uses the edges of a raster cell to define its location.
However, I am exporting a product to a user whose program defines
a raster cells location by its center point. Does anyone have any
suggestions on how I can get around this problem? Is there a way
that I can "shift" my raster cells to match the users?Thanks in advance,
Jim
jim@sar_ws.fb4.noaa.gov
Since a raster data file is really nothing more than a matrix of numbers, all
you really have to do is alter the header information that tells the program
where the matrix is geographically referenced. In GRASS, the header info is
found under the directory $LOCATION/cellhd. Basically, you're just going to
take 1/2 the resolution and add it to the westing and southing, and subtract
it from the easting and northing. This should obviously only be done to the
data that is going to be directly read by your other program, as GRASS will not
be happy with the alteration!
Regards,
--
Malcolm D. Williamson - Research Assistant E-mail: malcolm@cast.uark.edu
Center for Advanced Spatial Technologies Telephone: (501) 575-6159
Ozark Rm. 12 Fax: (501) 575-3846
University of Arkansas
Fayetteville, AR 72701