# Re: help with regridding

From: Adam Phillips <asphilli_at_nyahnyahspammersnyahnyah>
Date: Tue, 02 May 2006 15:05:55 -0600

Hi Jeff,

Depending on what you want here, Dennis Shea (just in my office) has
came up with a possible solution for you.

This is assuming you do not want an area average, and that you are fine
with subsampling:

newlat = (/38.,40.,42.,44.,46.,48./)
newlon = (/-80.0, -77.5, -75.0, -72.5, -70.0, -67.5, -65.0/)
arr2x25 = finarr({newlat},{newlon})

newlat2 = (/36.,40.,44.,48.,52/)
newlon2 = (/-80.,-75.,-70.,-65.,-60./)
arr4x5 = finarr({newlat2},{newlon2})

If this isn't what you are looking for let us know.
Adam

Jeff Van Dorn wrote:
> Hello,
>
> 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 regridding.
>
> Below is a portion of the script that I'm executing, and I've uploaded
> my output images to:
>
> http://temagami.tosm.ttu.edu/~jvandorn
>
> 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
> _______________________________________________
> ncl-talk mailing list
> ncl-talk_at_ucar.edu
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk

```--
--------------------------------------------------------------
Adam Phillips			             asphilli_at_ucar.edu
National Center for Atmospheric Research   tel: (303) 497-1726
ESSL/CGD/CAS                               fax: (303) 497-1333
P.O. Box 3000
Boulder, CO 80307-3000	  http://www.cgd.ucar.edu/cas/asphilli
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ncl-talk mailing list
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Received on Tue May 02 2006 - 15:05:55 MDT

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