You don't want to regrid and you shouldn't have to, even though that's what
other packages do. You can subset the data via Slab and then reproject via
coordinate warping (i.e., the data and topology remain invariant).
I wrote several things eons ago, which are available and explain this idea,
which may be helpful. Take a look at a tutorial at
http://www.research.ibm.com/dx/proceedings/cart/index.htm
One version of the referenced toolkit is in the 1996 DX Bonuspak. See, for
example,
http://www.research.ibm.com/dx/bonuspak/html/bonuspak216.html
http://www.research.ibm.com/dx/bonuspak/html/bonuspak222.html
A somewhat newer package with more examples is at
http://opendx.npaci.edu/bin/dx_examples.tar.gz
If you want to see a number of examples, papers, etc., look at
http://www.research.ibm.com/people/l/lloydt and
http://www.research.ibm.com/weather/vis/w_vis.htm
Ray D Wright <[EMAIL PROTECTED]>@opendx.watson.ibm.com on 04/05/2003
09:35:23 AM
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Subject: [opendx-users] Regridding projected geographic data
Hello,
I'm new to dx, and would like to find a way to do regridding of data
from one geographic projection to a target, smaller, grid with a
different projection. Somewhere along the way, it would be useful to see
the land outlines (of Europe, & W.Asia) for orientation of the output grid.
Specifically, I need to read in an ASCII file with x,y coordinates of a
Polar Stereographic grid, plus a value for each grid square (annual
emission of sulphur dioxide, say), then I need to visualise it, with the
land and nation outlines of Europe and W.Asia on a Lambert Conformal
grid, Then I need to overlay a Lambert Conformal output grid (covering
just the UK, say) and output an ASCII three-column file (x,y,emission
value) for all cells of the output grid.
I know this sort of thaing has been done in (expensive) professional GIS
systems, and I'm sure it can be done in dx. If anybody has any ideas on
this, I'd be very interested to hear from you.
Ray Wright
