Re: [ferret_users] Listing gridded data to triplets

[Jaison Kurian <jaison@xxxxxxxxxxxxxxxxxx>]

Hi Bill,
          I think the easy way to do this is using the REPEAT loop.
Here is an example with monthly_navy_winds dataset available with Ferret.
Please find the explanations inside the example. Let me know if you have
any difficulties.

Regards,

Jaison

!-------------------------------------------------------------------------
\ cancel mode verify
!
! Example : To list variable to an ascii file along with I,J,L indices
!.....................................................................

   set data monthly_navy_winds      ! dataset,  change it accordingly

   let var = uwnd[d=1]              ! variable, change it accordingly

   define symbol ascii = myfile.txt ! output ascii filename

   cancel reg/all                   ! remove this and use "set reg" if needed

   let ilo = `var,r=istart`
   let ihi = `var,r=iend`
   let jlo = `var,r=jstart`
   let jhi = `var,r=jend`
   let llo = `var,r=lstart`
   let lhi = `var,r=lend`

   ! 1. change the format statement as needed
   !
   ! 2. interchange the positions of I and J loop to get I varying faster
   !      than J
   !
   ! 3. col1  col2  col3  col4
   !
   !     L     J     I     VAR
   !
   ! 4. The script may take considerable time to finish if the number of
   !      data points are large...be patient

   sp rm -f ($ascii)
   REPEAT/L=`llo`:`lhi` ( ;\
     REPEAT/J=`jlo`:`jhi` ( ;\
       REPEAT/I=`ilo`:`ihi` ( ;\
          List/nohead/file=($ascii)/FORMAT=(2x,3(f6.1,3x),f10.4)/quiet/APPEND 
`L`,`J`,`I`, uwnd ;\
       ) ;\
     ) ;\
   )

!-------------------------------------------------------------------------

On Wed, 12 Apr 2006, Gustafson, William I wrote:

> Hi,
>
> Iım sure this question has arisen before, but I havenıt found the answer in
> the archive. I am using Ferret to analyze some data that is read in from
> gridded netCDF files with the resulting grid being (I,J,T). How can I get
> Ferret to list the results to a text file with each line containing the
> indices for time, I and J followed by the value? Each line would only
> contain data from one grid cell and time, first incrementing by the
> locations, and then incrementing by the times. Essentially, it would be
> something like the following for a 2x2 grid:
>
>    t1   i1   j1   value(i1,j1,t1)
>    t1   i1   j2   value(i1,j2,t1)
>    t1   i2   j1   value(i2,j1,t1)
>    t1   i2   j2   value(i2,j2,t1)
>    t2   i1   j1   value(i1,j1,t2)
>    etc.
>
> The ordering of the I and J isnıt important, as long as it is predictable. I
> hope that makes sense.
>
> Thanks for any suggestions!
>
> -Bill
>
>
> --------------------------------------------------------------------
> William I. Gustafson Jr.
> Atmospheric Science and Global Change Division
> Pacific Northwest National Laboratory
> 3200 Q Ave., MSIN K9-30
> Richland, WA 99352
> (509)372-6110