Re: linint2_Wrap Regriding

The error message is telling you exactly what the error is.

V = cru1990->precipitation ==> V(12,360,720)

Your new lat/lon are (306,384)

newlon = fspan(-84.025,-64.875,384)
newlat = fspan(34.875,50.125,306)

Hence,

linint2_Wrap(V&longitude,V&latitude,V,True,newlon,newlat,0)

would be result in a (12,306,384) array.

So, you are trying to place a (12,306,384) array into a (12,360,720).
Like the error message says, "Dimension sizes of left hand side and
right hand side of assignment do not match."

Currently, NCL does not allow this. (It will in a future release.)

Change to:

Vnew = linint2_Wrap(V&longitude,V&latitude,V,True,newlon,newlat,0)
printVarSummary(Vnew)

On 8/13/12 9:28 PM, Ping Yang wrote:
> Hi Adam,
>
> I got a problem with the regridding using linint2_Wrap(it was working
> for the daily data) with a monthly data,
> the is an error showed:
> fatal:Dimension sizes of left hand side and right hand side of
> assignment do not match.
> I ncdump -c the data file:
> netcdf Global_Precipitation_CRU21_30min_mT1980 {
> dimensions:
> latitude = 360 ;
> longitude = 720 ;
> bnds = 2 ;
> time = UNLIMITED ; // (12 currently)
> variables:
> double latitude(latitude) ;
> latitude:long_name = "Latitude" ;
> latitude:standard_name = "latitude_north" ;
> latitude:units = "degrees_north" ;
> latitude:valid_range = -90., 90. ;
> latitude:actual_range = -90., 90. ;
> latitude:bounds = "longitude_bnds" ;
> latitude:axis = "y" ;
> double longitude(longitude) ;
> longitude:long_name = "Longitude" ;
> longitude:standard_name = "longitude_east" ;
> longitude:units = "degrees_east" ;
> longitude:valid_range = -180., 180. ;
> longitude:actual_range = -180., 180. ;
> longitude:axis = "x" ;
> double latitude_bnds(latitude, bnds) ;
> double longitude_bnds(longitude, bnds) ;
> int time(time) ;
> time:long_name = "Time" ;
> time:standard_name = "time" ;
> time:units = "months since 1980-01-01 00:00" ;
> time:axis = "t" ;
> time:actual_range = 0, 11 ;
> double minimum(time) ;
> double maximum(time) ;
> double average(time) ;
> double stddev(time) ;
> float precipitation(time, latitude, longitude) ;
> precipitation:long_name = "Glo_CRU21_Precipitation_mTS1980_30min" ;
> precipitation:standard_name = "Precipitation" ;
> precipitation:var_desc = "Precipitation" ;
> precipitation:missing_value = -999.f ;
> precipitation:_FillValue = -999.f ;
> precipitation:scale_factor = 1.f ;
> precipitation:add_offset = 0.f ;
> precipitation:actual_range = 0.f, 1832.9f ;
>
> // global attributes:
> :Conventions = "CF-1.2" ;
> :title = "Glo_CRU21_Precipitation_mTS1980_30min" ;
> :data_type = "continuous" ;
> :domain = "Global" ;
> :subject = "precipitation" ;
> :references = ;
> :institution = ;
> :source = ;
> :comments = ;
> data:
>
> latitude = -89.75, -89.25, -88.75, -88.25, -87.75, -87.25, -86.75,
> -86.25,
> -85.75, -85.25, -84.75, -84.25, -83.75, -83.25, -82.75, -82.25,
> -81.75,
> -81.25, -80.75, -80.25, -79.75, -79.25, -78.75, -78.25, -77.75,
> -77.25,
> ......................
> 77.25, 77.75, 78.25, 78.75, 79.25, 79.75, 80.25, 80.75, 81.25, 81.75,
> 82.25, 82.75, 83.25, 83.75, 84.25, 84.75, 85.25, 85.75, 86.25, 86.75,
> 87.25, 87.75, 88.25, 88.75, 89.25, 89.75 ;
>
> longitude = -179.75, -179.25, -178.75, -178.25, -177.75, -177.25,
> -176.75,
> -176.25, -175.75, -175.25, -174.75, -174.25, -173.75, -173.25,
> -172.75,
> ..........................
> 168.75, 169.25, 169.75, 170.25, 170.75, 171.25, 171.75, 172.25,
> 172.75,
> 173.25, 173.75, 174.25, 174.75, 175.25, 175.75, 176.25, 176.75,
> 177.25,
> 177.75, 178.25, 178.75, 179.25, 179.75 ;
>
> time = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ;
> }
> the longitude and latitude is increasing monotonically
> and I used the following code to do the regridding:
>
> cru1990=addfile(idCRU+"Global_Precipitation_CRU21_30min_mT1980.nc","r");
>
> V=cru1990->precipitation(:,:,:)
>
> newlon = fspan(-84.025,-64.875,384)
>
> newlat = fspan(34.875,50.125,306)
>
> ;************************************************
>
> ; interpolate to new grid use linint2_Wrap function
>
> ;***********************************************
>
> V=linint2_Wrap(V&longitude,V&latitude,V,True,newlon,newlat,0)
>
>
> and there was an error:
>
> fatal:Dimension sizes of left hand side and right hand side of
> assignment do not match.
>
> Could anyone can help me on this?(Please let me know if there is a place
> to upload my sample file).
>
> Looking forward to hearing from you.
>
> Regards,
>
> Ping
> On Thu, May 17, 2012 at 12:45 PM, Adam Phillips <asphilli@ucar.edu
> <mailto:asphilli@ucar.edu>> wrote:
>
> Hi Ping,
> I think you are on the right track, but you do not need to subset the
> input array. (I am guessing that you are getting null values around the
> perimeter of your new grid.) When it comes to regridding one needs
> to make
> sure that the input latitudes and longitudes and the output
> latitudes and
> longitudes are in the same range, and flow in the same direction. You
> state you want your grid on negative longitudes, which is fine, but that
> means your input longitudes need to span the same range as well. So, I
> would recommend reading in the input data in its' entirety, flipping the
> latitudes, then use lonFlip to convert the longitudes from 0:360 to
> -180:180:
>
> pres=in->pres(:,::-1,:) ; ::-1 = flip latitudes
> pres = lonFlip(pres)
> printVarSummary(pres) ; lats should run from S->N, and lons from
> -180:180
>
> newlon = fspan(-84.025,-64.875,383)
> newlat = fspan(34.875,50.125,305)
> newlat@units = "degrees_north"
> newlon@units = "degrees_east"
> newsst=linint2_Wrap(pres&lon,pres&lat,pres,True,newlon,newlat,0)
>
> That should be it. If that doesn't work or if you have further questions
> please respond to ncl-talk.
> Best regards,
> Adam
>
>
> > Dear NCL user,
> >
> > I am doing interpolation from the PSD data(daily T62 Gaussian grid
> > (192x94)
> > 88.542N - 88.542S, 0E - 358.125E) to a 3 minute*3minute lon/lat
> regular
> > grid, I have encountered an issue with the bilinear interpolation
> with the
> > linint2_Wrap function (Interpolates from a rectilinear grid to
> another
> > rectilinear grid using bilinear interpolation, and retains
> metadata)with
> > NCL, because I've got invalid values(some of of the value are
> null). I
> > used
> > this code (I used a NCEP/NCAR reanalysis data, which is available
> by this
> > link
> >
> ftp://ftp.cdc.noaa.gov/Datasets/ncep.reanalysis.dailyavgs/surface_gauss/pres.sfc.gauss.2006.nc)
> > :
> >
> > ;*************************************************
> > ; interpolation.ncl
> > ;
> > ; Concepts illustrated:
> > ; - Interpolating from one grid to another using bilinear
> interpolation
> > ; use linint2_Wrap function for the retrieving all the metadata
> > ;create a new file to include the interpolated variable
> > ;
> > ;************************************************
> > load "/usr/local/lib/ncarg/nclscripts/csm/contributed.ncl"
> > ;load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> > ;change $NCARG_ROOT to /usr/local directly.
> > ;************************************************
> > begin
> > ;open file to write variable to(a new netCDF file)
> > out=addfile("pres.sfc.gauss.2006.interpolated.nc
> <http://pres.sfc.gauss.2006.interpolated.nc>","c")
> > ;************************************************
> > ; read in netCDF file
> > ;************************************************
> > in = addfile("pres.sfc.gauss.2006.nc
> <http://pres.sfc.gauss.2006.nc>","r")
> > ;************************************************
> > ; read in pres
> > ;***********************************************
> > ;Use a subscript for change the dimension of pressure and also
> subset the
> > variable
> > pres=in->pres(time|:,{lat|34.875:50.125},{lon|95.975:115.125})
> > ;so the newPres is with the latitude increasing
> > ;***********************************************************
> > ;newlon = fspan(-84.025,-64.875,383)
> > newlon = fspan(95.975,115.125,383);convert to a (0,360) instead of
> > (-180,+180)
> > newlat = fspan(34.875,50.125,305)
> > newlat@units = "degrees_north"
> > newlon@units = "degrees_east"
> > ;************************************************
> > ; interpolate to new grid use linint2_Wrap function
> > ;***********************************************
> > newsst=linint2_Wrap(pres&lon,pres&lat,pres,True,newlon,newlat,0)
> > ;*************output variable to new file****************
> > out->pres=newsst
> > end
> >
> > Actually I need the domain range is from lon(-84.025,-64.875,383),
> > lat(34.875,50.125,305) in the lon/lat regular grid, Can I ask you
> what
> > will
> > be the correct range in the Gaussian grid lon 95.975:115.125? I tried
> > several times, it seems that I am confused by the translation,
> >
> > Am I use the right function for this interpolation? I will be
> appreciated
> > if you can point out where is the problem ?
> >
> > Best Regards,
> >
> > Ping
> >
> > --
> > Ping Yang, Ph.D.
> > CUNY Environmental Crossroads Initiative
> > Marshak Science Building - Suite 925
> > The City College of New York - CUNY
> > 160 Convent Avenue, New York NY 10031
> > Phone: 212-650-5769
> > Fax: 212-650-7064
> > _______________________________________________
> > ncl-talk mailing list
> > List instructions, subscriber options, unsubscribe:
> > http://mailman.ucar.edu/mailman/listinfo/ncl-talk
> >
>
>
> __________________________________________________
> Adam Phillips asphilli@ucar.edu <mailto:asphilli@ucar.edu>
> NCAR/Climate and Global Dynamics Division
> P.O. Box 3000 (303) 497-1726 <tel:%28303%29%20497-1726>
> Boulder, CO 80307-3000
> http://www.cgd.ucar.edu/cas/asphilli
>
>
>
>
>
>
>
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Received on Mon Aug 13 21:47:58 2012