help with regridding

From: Jeff Van Dorn <vandorn_at_nyahnyahspammersnyahnyah>
Date: Tue, 2 May 2006 15:17:19 -0500


I have an ascii grid file at a resolution of .125 x .125, which Adam
(Phillips) graciously helped me to be able to read into and plot with
NCL. However, now I have the task of having to upscale this data to
a larger grid (2x2.5 and also 4x5 - lat x lon). My attempts at
regridding might be producing the best results possible, however I'd
much appreciate it if someone could take a look and see if there's
something I'm doing incorrectly.

As this data that I have is for the northeast US only, and no ocean
or Canadian data is present I do have a rather slim boundary for the
data to fit in, and given the fact the my new grid will be
considerably larger than the existing grid, that might be why I have
so few grids that actually contain any data when I plot the larger
grid, but then again I might be doing something wrong with the

Below is a portion of the script that I'm executing, and I've
uploaded my output images to:

If anyone has any suggestions on how to get more grids in the larger
grid size to contain data, I would be most appreciative.
Alternatively, I'd also be grateful if someone would just be able to
confirm that this is the best that I can do with the larger grid size
that I'd like to have.

Thanks much,
Jeff Van Dorn

         finarr = new((/dimsizes(lat),dimsizes
(lon)/),"float",-999.) ; set up array to house
         finarr!0 = "lat" ; data
         finarr&lat = lat
         finarr!1 = "lon"
         finarr&lon = lon

         do gg = 0,dimsizes(a(:,0))-1 ; loop thru each line, use
coordinate subscripting to
            finarr({a(gg,0)},{a(gg,1)}) = (/ a(gg,2) /) ; place data
in finarr
         end do

         ; This is what I've added
         newlat = (/38,40,42,44,46,48/)
         newlon = (/-80.0, -77.5, -75.0, -72.5, -70.0, -67.5, -65.0/)
         newlat_at_units = "degrees_north"
         newlon_at_units = "degrees_east"
         newlat!0 = "lat"
         newlat&lat = newlat
         newlon!0 = "lon"
         newlon&lon = newlon

         ; attempt the regrid
         newvar = linint2( lon, lat, finarr, False, newlon, newlat, 0)
         newvar!0 = "lat" ; data
         newvar&lat = newlat
         newvar!1 = "lon"
         newvar&lon = newlon

         ;Then plot and stuff
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Received on Tue May 02 2006 - 14:17:19 MDT

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