Re: Grads Binary file

I'm a GrADS user too..

During my transition to NCL I too am facing the same problem. What I do is
to convert the Grads file to NetCDF with the 'lats4d' package in Grads.
Then use the 'addfile' command to read the netcdf.

Else, to read the binary file of Grads, one has to supply all the
attributes explicitly to the data read with 'fbindirread'

Please see a NCL script segment.

         fname = "/user1/prince/Reynolds/1x1/sstan_jan1982_dec2002.grd"

         ntim = 252
         nlat = 180
         nlon = 360

         lonL = 0
         lonR = 360
         latS = -89.5
         latN = 89.5

         years = sprinti("%4i",ispan(1982,2002,1)) ; write integers
as string
         months = sprinti("%0.2i", ispan(1,12,1)) ; ditto for
months

         time = new(dimsizes(years)*dimsizes(months),"integer") ; create
time array
         k=0
         do i=0,dimsizes(years)-1
              do j = 0, dimsizes(months)-1
                    time(k)=stringtointeger(years(i)+months(j)) ; combine to
strings
                    k=k+1 ; and
convert to int
              end do
         end do

         lat = fspan(latS,latN,nlat)
         lat_at_units = "degrees_north"

         lon = fspan(lonL,lonR,nlon)
         lon_at_units = "degrees_east"

         sst = fbindirread(fname,0,(/ntim,nlat,nlon/), "float")

         sst!0 = "time"
         sst!1 = "lat"
         sst!2 = "lon"

         time_at_long_name = "time"
         time_at_units = "yyyymm"

         sst&time = time
         sst&lat = lat
         sst&lon = lon
         sst@_FillValue = -32767

------------------------------------------

Hope this helps!
Prince

On Fri, 3 Mar 2006, Dennis Shea wrote:

>
> Well, I am not a GrADS user :-)
> so I do not know. You may have to go to the GrADS
> WWW and read about it.
>
> GrADS format is basically a flat binary file.
>
> I speculate that the following will work.
>
> rain = fbindirread("1991new.grads", 0, 365, "float")
> print(rain)
>
> ==========================================================================
> > On Thu, 2 Mar 2006, sahana_paul wrote:
>>
> Hi,
> I have dat in grads binary file say temp.grads and descripter file
> temp.ctl and temp.map also. Is it possible to use this file in NCL or anyother
> way to convert it netcdf, grib, or any other file format.
>
>> I have station data, so how to assaign the lat lon to the
>> perticular station.
>> my ctl file is,
>>
>> dset ^1991new.grads
>> dtype station
>> stnmap 1991new.map
>> undef -9999.00
>> title rain
>> tdef 365 linear 01jan1991 1dy
>> vars 1
>> rain 0 99 rain
>> endvars
>>
>> in that case I cannot use the grads2nc.
>>
>> regards
>>
>> sahana
>>
>
> _______________________________________________
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>

-- 
Prince K XAVIER
Centre for Atmospheric and Oceanic Sciences 
Indian Institute of Science 
Bangalore - 560 012 
INDIA 
http://caos.iisc.ernet.in/hpg/students/prince.html
__________________________________________________ 
Phone No. 
+91 80 2293 2505 (Extn:201)
+91 98808 19172  (Mobile)
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