Hi Adam. Thank you for suggesting that I use linint2_Wrap.
But does allow me to do nearest neighbor?
But a few other recent ncl_talk postings mention the function "area_hi2lores."
would area_hi2lores work just like linint2? I am trying to go from a
higher resolution to a lower resolution.
A little confused.
Bold
On Thu, Jun 11, 2009 at 3:34 PM, Adam Phillips<asphilli_at_ucar.edu> wrote:
> Hi Bold,
> triple2grid is meant to be used when you want to put randomly spaced data
> (say, station data) onto a grid. As you are simply regridding from one grid
> to another, I would use linint2_Wrap:
> http://www.ncl.ucar.edu/Document/Functions/Contributed/linint2_Wrap.shtml
>
> If the input field was global, didn't have any missing values, and was not a
> field bounded by 0 (for example, precipitation), I would use one of the
> spherical harmonic functions:
> http://www.ncl.ucar.edu/Document/Functions/regrid.shtml
> (All the f2* and g2* functions are spherical harmonic regridding functions.)
> Good luck, and welcome to NCL.
> Adam
>
> B N wrote:
>>
>> Hi. NCL beginner here. I have spent an enormous amount of time going
>> through beginner lessons to use NCL for my research. I like it.
>> Unfortunately, I've encountered my first error that I can't figure
>> out. I have searched previous posts
>> and I don't see that others have encountered
>> this with triple2grid. I don't see any.
>>
>> I use the triple2grid function to regrid 1/4 degree precipitation data
>> (CMORPH) to a 1/2 degree grid (ncl 59>, below). After I regrid the
>> data, my data is missing. I don't know why.
>> ncl 62> printMinMax(rNEW,True)
>> (0)
>> (0) min=-999 max=-999
>>
>> Could I have some help with understanding this?
>> Thank you for your time.
>> -Bold Khan
>>
>> Fu School of Engineering,
>> Earth and Environmental Engineering
>> Columbia University
>>
>> mongol :CMORPH gkhan$ ncl
>> Copyright (C) 1995-2009 - All Rights Reserved
>> University Corporation for Atmospheric Research
>> NCAR Command Language Version 5.1.0
>> The use of this software is governed by a License Agreement.
>> See http://www.ncl.ucar.edu/ for more details.
>> ncl 0> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>> ncl 1> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>> ncl 2> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>> ncl 3> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"
>> ncl 4> load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"
>> ncl 5> a = addfile("cmorph_SOP3_.25nc","r")
>> ncl 6> rain_new = a->p_rate
>> ncl 7> rain_new=rain_new(:,::-1,:)
>> ncl 8> printVarSummary(rain_new)
>>
>>
>> Variable: rain_new
>> Type: float
>> Total Size: 663552000 bytes
>> 165888000 values
>> Number of Dimensions: 3
>> Dimensions and sizes: [time | 240] x [lat | 480] x [lon | 1440]
>> Coordinates:
>> time: [2.00609e+09..2.006093e+09]
>> lat: [-59.875..59.875]
>> lon: [0.125..359.875]
>> Number Of Attributes: 3
>> units : mm/hr
>> long_name : CMORPH
>> _FillValue : -9999
>> ncl 9> printMinMax(rain_new,True)
>> (0)
>>
>> (0) CMORPH: min=0 max=40.3708
>> ncl 10> nlat = 480
>> ncl 11> mlon = 1440
>> ncl 12> time = ispan(1,dimsizes(rain_new(:,0,0)),1)
>> ncl 13> lat = rain_new(0,:,0)
>> ncl 14> lon = rain_new(0,0,:)
>> ncl 15> lat!0 = "lat"
>> ncl 16> lat&lat = lat
>> ncl 17> lat_at_units = "degrees_north"
>> ncl 18> lon!0 = "lon"
>> ncl 19> lon&lon = lon
>> ncl 20> lon_at_units = "degrees_east"
>> ncl 21> ylat = lat
>> ncl 22> xlon = lon
>> ncl 23> ylat!0 = "Lat"
>> ncl 24> xlon!0 = "Lon"
>> ncl 25> lat2d = new((/480,1440/),float) ; CMORPH documentation
>> ncl 26> lon2d = new((/480,1440/),float)
>> ncl 27> lat2d!0 = "Lat"
>> ncl 28> lat2d!1 = "Lon"
>> ncl 29> lon2d!0 = "Lat"
>> ncl 30> lon2d!1 = "Lon"
>> ncl 31> lat2d_at_units = "degrees_north"
>> ncl 32> lon2d_at_units = "degrees_east"
>> ncl 33> ;=============; 2d grid coordinates should match the rain array.
>> ncl 34> do i=0,479
>> ncl 35> lon2d(i,:) = xlon(:)
>> ncl 36> end do
>> ncl 37> do i=0,1439
>> ncl 38> lat2d(:,i) = ylat(:)
>> ncl 39> end do
>> ncl 40> NLAT = 240
>> ncl 41> MLON = 720
>> ncl 42> Lat = fspan(59.875,-59.875,240) ; lat for regridding to 0.5 degree
>> ncl 43> Lon = fspan(0.125,359.875,720) ; lon for regridding to 0.5 degree
>> ncl 44> Lat!0 = "lat"
>> ncl 45> Lat_at_units = "degrees_north"
>> ncl 46> Lat&lat = Lat
>> ncl 47> Lon!0 = "lon"
>> ncl 48> Lon_at_units = "degrees_east"
>> ncl 49> Lon&lon = Lon
>> ncl 50> rNEW = new
>>
>> ((/dimsizes(rain_new(:,0,0)),NLAT,MLON/),typeof(rain_new),getFillValue(rain_new))
>> ;New rain array
>> ncl 51> rNEW!0 = "time"
>> ncl 52> rNEW&time = time
>> ncl 53> rNEW!1 = "lat"
>> ncl 54> rNEW&lat = Lat
>> ncl 55> rNEW!2 = "lon"
>> ncl 56> rNEW&lon = Lon
>> ncl 57> print("Regridding with Triple2Grid Now.")
>> (0) Regridding with Triple2Grid Now.
>> ncl 58> do ii = 0,dimsizes(rNEW(:,0,0))-1 ;;;;;;Should be 0,239
>> ncl 59> rNEW(ii,:,:) = triple2grid(ndtooned(lon2d), ndtooned(lat2d),
>> ndtooned(rain_new(ii,:,:)),Lon,Lat,False)
>> ncl 60> end do
>> ncl 61> printVarSummary(rNEW)
>> (0)
>> (0) min=-999 max=-999
>> ncl 63> exit
>> _______________________________________________
>> ncl-talk mailing list
>> List instructions, subscriber options, unsubscribe:
>> 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
>
_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Fri Jun 12 2009 - 05:39:26 MDT
This archive was generated by hypermail 2.2.0 : Mon Jun 15 2009 - 08:53:05 MDT