[ncl-talk] write variable in do loop

[Alessandra Giannini]

Hi there,

[it's a madam speaking, actually!]
You should always reply to ncl-talk, not just to the person who responds…

It would help if you explained what is not working… 
At any rate, what is the structure of the variable you call here:

>   td = wrf_user_getvar(a,"td",it)


if it has all the levels you need, just write it out.

It may be that these two lines that define your variables need to sit outside/before the loops:

>   td = wrf_user_getvar(a,"td",it)
>   p  = wrf_user_getvar(a,"pressure",it)


Otherwise you redefine them each time.
Please think through what you want to accomplish, and the correct order of the steps to get there.








-- 
Alessandra Giannini
IRI for Climate and Society - The Earth Institute at Columbia University
P.O. Box 1000, Palisades NY 10964-8000
phone/fax: +1 845 680-4473/4864 - email: alesall at iri.columbia.edu

On Sep 10, 2015, at 6:54 AM, Ancy Thomas <ancyt.thomas at gmail.com> wrote:

> Hello Sir,
> 
> Thanks for the response.
> 
> Yes, I want to write the data variable for each level in a loop. The program is given below: How should I modify .
> 
> ************************************************
> begin
> datadir = systemfunc("tail -1 fil")
> FILES = systemfunc ("ls -1 " + datadir + "wrfout_d02* " )
> numFILES = dimsizes(FILES)
> ;;***************Pressure levels **********
>  plevs = (/ 925., 850., 700., 600., 500., 300., 200./)   ; pressure levels to plot
>  nlevels         = dimsizes(plevs)     ; number of pressure levels
> 
> do ifil = 0,numFILES-1
>    a = addfile(FILES(ifil)+".nc","r")
> 
> ; What times and how many time steps are in the data set
> times  = wrf_user_list_times(a)  ; get times in the file
>   ntimes = dimsizes(times)       ; number of times in the file
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> 
> ;Read in constant variables
>       xlat  = wrf_user_getvar(a, "XLAT",0)
>       xlon  = wrf_user_getvar(a, "XLONG",0)
>       hght   = wrf_user_getvar(a, "HGT",0)
> 
> ; writing data into netcdf format
>     system("rm -f wrfout.nc")
>     fw = addfile("wrfout.nc", "c")
> 
> ; writing the dimensions time, level, lat, lon
>   fw->xlat = xlat
>   fw->xlon = xlon
> 
> ;;*************************
>   do it = 0,ntimes-1               ; TIME LOOP
> 
>   do level = 0,nlevels-1                 ; LOOP OVER LEVELS
> 
>   pressure = plevs(level)
> 
>   td = wrf_user_getvar(a,"td",it)
>   p  = wrf_user_getvar(a,"pressure",it)
> 
>   td_plane(level,:,:) = wrf_user_intrp3d(td,p,"h",pressure,0.,False)
> 
>  end do ; end of level loop
>  end do ; end of time loop
>  end do ; end of files loop
>  end
> 
> 
> Thanks,
> Best regards,
> Ancy
> 
> 
> 
> On Thu, Sep 10, 2015 at 4:04 PM, Alessandra Giannini <alesall at iri.columbia.edu> wrote:
> 
> Hi there,
> 
> I am not familiar with the "wrf" commands you use, but you are asking it to overwrite levels with this line:
> 
> > fw->u_plane = u_plane
> 
> 
> Do you need to write the levels out separately, meaning do you need a do-loop to begin with?
> If you have all the data in a variable, it may be preferable to select the time and levels you want to write out with coordinate selection, and write out all in one go.
> 
> warm regards
> 
> 
> 
> 
> 
> --
> Alessandra Giannini
> IRI for Climate and Society - The Earth Institute at Columbia University
> P.O. Box 1000, Palisades NY 10964-8000
> phone/fax: +1 845 680-4473/4864 - email: alesall at iri.columbia.edu
> 
> On Sep 10, 2015, at 12:26 AM, Ancy Thomas <ancyt.thomas at gmail.com> wrote:
> 
> > Could anyone please help for this query.
> >
> >
> >
> > On Wed, Sep 9, 2015 at 6:04 PM, Ancy Thomas <ancyt.thomas at gmail.com> wrote:
> > Hello all,
> > Greetings!
> >
> > I want to write a variable in do loop. But it is writing the data only for the last level(200hpa), ie; data is getting over written for each level. How to save the u_plane data as array?
> >
> >
> > ;;***************Pressure levels **********
> >  plevs = (/ 925., 850., 700., 600., 500., 300., 200./)   ; pressure levels to plot
> >  nlevels         = dimsizes(plevs)     ; number of pressure levels
> >
> > ; writing data into netcdf format
> >     system("rm -f wrfout.nc")
> >     fw = addfile("wrfout.nc", "c")
> >
> >
> > ; writing the dimensions time, level, lat, lon
> >
> > ;  fw->xlev = xlev
> >   fw->xlat = xlat
> >   fw->xlon = xlon
> >
> >  do it = 0,ntimes-1               ; TIME LOOP
> >
> >  do level = 0,nlevels-1                 ; LOOP OVER LEVELS
> > u    = wrf_user_getvar(a,"U",it)
> >
> > u_plane    = wrf_user_intrp3d(u,p,"h",pressure,0.,False)
> >
> > fw->u_plane = u_plane
> >
> > end do ; level loop
> > end do ; time loop
> >
> > Kindly help to resolve the issue.
> >
> > Thank you,
> > With regards,
> > --
> > Ancy Thomas,
> > Computational Earth Science Group / HPC application Group
> > CDAC
> > Pune
> >
> >
> >
> >
> > --
> >
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> 
> 
> 
>