Re: (corrected mail)....use of scat2grid command(help)

["Yogesh K. Tiwari" <ktiwari@xxxxxxxxxxxxxxx>]

Hello Jaison,

Many thanks for help.

The attched script wrote by you solved the problem and works fine.

Regards,
Yogesh


 Kurian wrote:
> Hi Tiwari,
>             Your mail serves as a good reminder. It seems that
> the scattered or point data is defined over 2-3 days. So the
> only way possible is take all the scattered data assuming the
> mean time.
>
>   Have a look at the attached jnl file (regrid2reg.jnl). If it
> is working fine and you are through, then post a summary to the
> mailing list for the reference of other users. Or if you have
> any problem, let me know.
>
> with regards 
> Jaison
>
> On Wed, 29 Dec 2004, Yogesh K. Tiwari wrote:
>
>
> > Hello,
> >
> > This question once I asked in the list but could NOT
> > solve my problem.
> >
> > I would be happy if you can help me.
> >
> > I want to use scat2grid command to convert 1-d point data in to
> > 2-d grided data,
> >
> > ################################
> > The point data looks like :-
> >
> >      currently SET data sets:
> >     1> ./CO2_January_2003.nc  (default)
> >  name     title       I         J         K         L
> >  YEAR                ...       ...       ...       1:186039
> >  MONTH               ...       ...       ...       1:186039
> >  DAY                 ...       ...       ...       1:186039
> >  HOUR                ...       ...       ...       1:186039
> >  MINUTE              ...       ...       ...       1:186039
> >  LON                 ...       ...       ...       1:186039
> >  LAT                 ...       ...       ...       1:186039
> >  CO2_T                 ...       ...       ...     1:186039
> >
> >
> > ###########################
> > The grided data which I want to convert from above
> > should be like:-
> >
> >      currently SET data sets:
> >     1> ./ecmwf_co2_jan2003.nc  (default)
> >
> >  name     title        I         J         K         L
> >  LON                  1:360     ...       ...       ...
> >  LAT                  1:180     ...       ...       ...
> >  CO2_T                1:360     1:180     ...
> >
> >
> > Many thansk for your help.
> >
> > Regards,
> > Yogesh
>
>
> ------------------------------------------------------------------------
>
> \ cancel mode verify
> !
> ! dataset 1 contains the gridded data(ecmwf_co2_jan2003.nc)
> ! dataset 2 contains the scattered/point data (CO2_January_2003.nc)
> !  
> ! grid for dataset 1 is 360x180
> ! lat and lon is given in seperate variables for the dataset 1.
> ! 
> !
> !---------------------------------------------------------
>
> ! open datasets
>
>      set data ecmwf_co2_jan2003.nc  ! keep the order of datasets
>      set data CO2_January_2003.nc   !   unchanged
>
> ! define destination axes from lat and lon in ecmwf_co2_jan2003
>
>      define axis/x/units=longitudes/from_data xlon=lon[d=1]
>      define axis/y/units=latitudes/from_data  ylat=lat[d=1]
>      define grid/x=xlon/y=ylat gcom
>
> ! regrid the variable co2_t in ecmwf_co2_jan2003 to regular lat-lon grid
>
>      let co2_ecmwf = co2_t[d=1,g=gcom@ASN]
>      set var/title="CO2 from ECMWF"/units="ppmv" co2_ecmwf
>
> ! regrid the co2_t in CO2_January_2003.nc to the above grid using scat2grid
>
>      ! define the radius and cutoff values for scat2grid function
>
>      define symbol radius = 0.25   ! ideal values for a 0.25 grid 
>      define symbol cutoff = 2.0    !  with possible minimum interpolation errors
>   
>      let lon_1D = XSEQUENCE(lon[d=2])
>      let lat_1D = XSEQUENCE(lat[d=2])
>      let co2_1D = XSEQUENCE(co2_t[d=2]) 
>      let co2_obs = scat2gridgauss_xy(lon_1D,lat_1D,co2_1D,\
>              x[gx=gcom],y[gy=gcom],($radius),($radius),($cutoff),($cutoff))       
>      set var/title="CO2 from Obs."/units="ppmv" co2_obs
>
> ! now the variables co2_ecmwf & co2_obs will be on the same grid and
> !  you can compare both. If you want to save this to a new NetCDF file
> !  (strongly recommended)
>
>     ! sp rm -f co2_ecmwf_obs.nc
>     ! save/file=co2_ecmwf_obs.nc/append co2_ecmwf,co2_obs 


--

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Yogesh K. Tiwari,
Max-Planck Institute for Biogeochemistry,
Beutenberg Campus, Hans-Knoell-Strasse 10,
D-07745 Jena,
Germany

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