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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi Dennis,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><br>
Thanks for the help. However after looking at example 20 I noticed all the example really required/needed was a destination grid lat/lon arrays so I simply created arrays of the same lat/lon end points but double the total points (to go from 64 to 32km.)
The regridding worked, but unfortunately it took the data and actually interpolated it to 32km instead of simply “slicing up the data”. Please see the attached figure if that makes more sense.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">-Marc<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Dennis Shea [mailto:shea@ucar.edu]
<br>
<b>Sent:</b> Saturday, November 22, 2014 2:45 PM<br>
<b>To:</b> Marcella, Marc<br>
<b>Cc:</b> ncl-talk@ucar.edu<br>
<b>Subject:</b> Re: [ncl-talk] regrid from 64km to 32km<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">NCL has no explicit function to create the 32km lat/lon locations.<o:p></o:p></p>
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<p class="MsoNormal">However, if this is "test input file" maybe you could create test set via<o:p></o:p></p>
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<p class="MsoNormal">the following which was extracted from an example<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"> aDataDir = "./"<br>
aFileName = "wrfout_d01_2003-07-15_00:00:<a href="http://00.nc" target="_blank">00.nc</a>"<br>
aFile = aDataDir+aFileName<br>
a = addfile(aFile,"r") ; a is the wrf output with the format of rcm<br>
<br>
xlat = a->XLAT(0,:,:)<br>
xlon = a->XLONG(0,:,:)<o:p></o:p></p>
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<p class="MsoNormal"> dat = a-><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">TOT_PRCP
</span><o:p></o:p></p>
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<p class="MsoNormal"><br>
dimll = dimsizes(xlat)<br>
nlat = dimll(0)<br>
mlon = dimll(1)<br>
<br>
NLAT = 2*nlat-1 ; make large array<br>
MLON = 2*mlon-1<br>
XLAT = new( (/NLAT,MLON/), typeof(xlat))<br>
XLON = new( (/NLAT,MLON/), typeof(xlat))<o:p></o:p></p>
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<p class="MsoNormal"> DAT = new( (/NLAT,MLON/), typeof(xlat))<o:p></o:p></p>
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XLAT(0:NLAT-1:2,0:MLON-1:2) = xlat ; populate with every<br>
XLON(0:NLAT-1:2,0:MLON-1:2) = xlon ; other value<br>
poisson_grid_fill(XLAT, False, 1, 1500, 1e-2, 0.6, 0)<br>
poisson_grid_fill(XLON, False, 1, 1500, 1e-2, 0.6, 0)<br>
poisson_grid_fill(DAT , False, 1, 1500, 1e-2, 0.6, 0) ; <== could be slow<br>
<br>
copy_VarMeta(xlat,XLAT)<br>
copy_VarMeta(xlon,XLON)<br>
<br>
printVarSummary(XLAT)<br>
printVarSummary(XLAT)<br>
;print("XLAT: "+XLAT(:,0) +" "+XLAT(:,MLON/2) +" "+ XLAT(:,MLON-1))<br>
;print("XLON: "+XLON(0,:) +" "+XLON(NLAT/2,:) +" "+ XLON(NLAT-1,:))<br>
<br>
wks = gsn_open_wks("x11","tstgrid")<br>
;gsn_define_colormap(wks,"BlAqGrYeOrRe")<br>
<br>
latlonres = True<br>
latlonres@gsnDraw = False<br>
latlonres@gsnFrame = False<br>
latlonres@cnLineThicknessF = 2<br>
latlonres@tiMainString = "Original Grid"<br>
<br>
latlonres@cnLineColor = "red"<br>
plotLat = gsn_contour(wks,xlat,latlonres)<br>
latlonres@cnLineColor = "blue"<br>
plotLon = gsn_contour(wks,xlon,latlonres)<br>
overlay(plotLat,plotLon) ; overlay on map<br>
draw(plotLat)<br>
frame(wks)<br>
<br>
latlonres@tiMainString = "Destination Grid"<br>
latlonres@cnLineColor = "red"<br>
plotLAT = gsn_contour(wks,XLAT,latlonres)<br>
latlonres@cnLineColor = "blue"<br>
plotLON = gsn_contour(wks,XLON,latlonres)<br>
overlay(plotLAT,plotLON) ; overlay on map<br>
draw(plotLAT)<br>
frame(wks)<br>
<br>
<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Fri, Nov 21, 2014 at 12:36 PM, Marcella, Marc <<a href="mailto:MMarcella@air-worldwide.com" target="_blank">MMarcella@air-worldwide.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi Dennis,</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><br>
Is there a way to do this if I in fact I don’t have a destination grid file like example 20 has? I am looking to create said destination grid file.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Dennis Shea [mailto:<a href="mailto:shea@ucar.edu" target="_blank">shea@ucar.edu</a>]
<br>
<b>Sent:</b> Friday, November 21, 2014 12:02 PM<br>
<b>To:</b> Marcella, Marc<br>
<b>Cc:</b> <a href="mailto:ncl-talk@ucar.edu" target="_blank">ncl-talk@ucar.edu</a></span><o:p></o:p></p>
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<p class="MsoNormal"><br>
<b>Subject:</b> Re: [ncl-talk] regrid from 64km to 32km<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Based on the printVarSummary which shows the named dimensions as<br>
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">
[Time | 8760] x [south_north | 106] x [west_east | 123]</span><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">You hacv a WRF grid (curvilinear) grid.</span><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt"><br>
<a href="http://www.ncl.ucar.edu/Applications/ESMF.shtml" target="_blank">http://www.ncl.ucar.edu/Applications/ESMF.shtml</a><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">Example 20 (also, Example 16)<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">This is going from high resolution to low resolution but you could just use your 64km res file as input and<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">specify the 'destination' 32 km grid.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">Note: you are interpolating precipitation. Since it is a test, bilinear would be fine. However, the conserve method may be better for some applications.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Good luck
<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On Fri, Nov 21, 2014 at 9:44 AM, Marcella, Marc <<a href="mailto:MMarcella@air-worldwide.com" target="_blank">MMarcella@air-worldwide.com</a>> wrote:<o:p></o:p></p>
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<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">1)</span><span style="font-size:7.0pt;color:#1F497D">
</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Yes, I meant it would be a misrepresentation of resolution since it will be at 32km physically but in reality it is 64km information.</span><o:p></o:p></p>
<p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">2)</span><span style="font-size:7.0pt;color:#1F497D">
</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I have a 64km resolution dataset that I want to slice up into 32 km resolution for example going from say a 50x50 grid to 100x100 grid (4x total points) I attached an illustration
if this makes it clearer. </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.25in">
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">The original data is curvilinear (output from WRF data) but this data itself is plucked out of the wrfout files and placed onto a grid that knows nothing about the lat/lon and I
am fine keeping it in a rectilinear grid as seen here by the printVarSummary: </span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Variable: TOT_PRCP</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.25in">
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Type: float</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Total Size: 456851520 bytes</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">114212880 values</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Number of Dimensions: 3</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Dimensions and sizes: [Time | 8760] x [south_north | 106] x [west_east | 123]</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.25in">
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Coordinates:
</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Number Of Attributes: 3</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">_FillValue : 9.96921e+36</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.25in">
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">units : mm/hr</span><o:p></o:p></p>
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<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">description : Total hourly precipitation accumulation
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thank you for your help with this!</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Marc</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Dennis Shea [mailto:<a href="mailto:shea@ucar.edu" target="_blank">shea@ucar.edu</a>]
<br>
<b>Sent:</b> Friday, November 21, 2014 11:27 AM<br>
<b>To:</b> Marcella, Marc; <a href="mailto:ncl-talk@ucar.edu" target="_blank">ncl-talk@ucar.edu</a><br>
<b>Subject:</b> Re: [ncl-talk] regrid from 64km to 32km</span><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">I think you have to provide more information.
<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">[1] Not sure what you mean by "this would be an incorrect regridding format/procedure". Do you mean going from low -resolution to high-resolution? There is nothing "incorrect" about
that. The issue is that the *effective resolution* would stll be 64km but the data are rendered on a 32km grid.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">[2] The rest of the question is obscure.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">[3] *ALWAYS* include a printVarsummary of the source variable.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> (a) Is the source grid rectilinear or curvilinear? If curvilinear, then linint2 is not the function to use.<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On Fri, Nov 21, 2014 at 7:58 AM, Marcella, Marc <<a href="mailto:MMarcella@air-worldwide.com" target="_blank">MMarcella@air-worldwide.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Hi NCL’ers,<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I would like to take a current dataset that is 64 km, say at dimensions j=106 x i=123 and “regrid” it such that the gridcells are just sliced up into 32km resolution grid cells,
ie the final product would have dimensions of 212x246. I do recognize that this would be an incorrect regridding format/procedure but I just need the grid for a test input file. I tried the linint2 regridding but this kept the first (lower left) 106x123
gridcells the original values and all the additional/new gridcells outside this box were FillValues. Is there an easy way to do this with a regrid or NCL function?<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Thanks for any help in advance!<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#888888"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#888888">Marc</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#888888"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#888888"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#888888"> </span><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt"><br>
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