Re: Writing netcdf files

Hi,

I suspect you may need to explicitly close each NetCDF file after
writing to it with a "delete(pot_evap)" at the end of your
doubly-nested loop.

As for the dimensions, I'm not clear on your intent, but from the
loop, were you wanting something more like:
   
    pot_evap->pet = pot(i,j,:,:) ;; rather than "pot_eval->pet =
pot"

Hope that helps...
Rick

On Mon, 27 Jan 2014 10:58:40 +0000
  Almami Johnson <almamij@gmail.com> wrote:
> Dear NCL users
>
> I'm trying to calculate monthly potential evapotranspiration based
>on
> Thornthwaite (1948). I have each monthly term in a file named
> something.year.month.nc. I have created this script to output each
> month for a given year in a file named output.year.month.nc.
> The problem is all the output.year.month.nc are similar which makes
>me
> think NCL is writing the same thing in all the output files. Could
>you
> please take a look at this script and tell me what is wrong with it?
> Another problem I'm facing is that the ncdump -h of the outputs
>looks like this:
>
> dimensions:
> time = UNLIMITED ; // (0 currently)
> ncl1 = 20 ;
> ncl2 = 12 ;
> latitude = 180 ;
> longitude = 280 ;
> variables:
> float pet(ncl1, ncl2, latitude, longitude) ;
> pet:units = "mm/month" ;
> pet:long_name = "Potential Evap" ;
> pet:_FillValue = 9.96921e+36f ;
>
> My question is how to output without ncl1 and ncl2 dimensions and
>have
> the time like time = UNLIMITED ; // (1 currently)
>
> Thanks for your help
> Almami
>
> -------------------------------------------------------------------------------------------------------------------
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>
> begin
>
> ;*****************************************************************************************
> ; Creating Function to Read at once Precip and Convert Calendar to
> Human Readable YYYYMM
> ;*****************************************************************************************
> undef("getPrecip")
> function getPrecip(fname[1]:string, vname[1]:string)
> local x
>
> begin
> f = addfile(fname, "r")
> x = f->$vname$(0,0,{-10:35},{-30:40}) ; read specified
>time period
> return(x)
> end
>
> undef("getPrecip1")
> function getPrecip1(fname[1]:string, vname[1]:string)
> local y
>
> begin
> f = addfile(fname, "r")
> y = f->$vname$(0,{-10:35},{-30:40}) ; read specified time
>period
> return(y)
> end
>
> ;*****************************************************************************************
> ; Creating a new variable corresponding to all the 12 months and
>getting each
> ;*****************************************************************************************
>
>
> reffile = addfile("ENSMEAN_Pre_paren_2004_05.nc", "r")
> refparam = reffile->t2m(:,0,{-10:35},{-30:40})
> printVarSummary(refparam)
>
> dim = dimsizes(refparam)
> ntime= dim(0)
> nlat = dim(1)
> nlon = dim(2)
>
> year=(/"1985","1986","1987","1988","1989","1990","1991","1992","1993","1994","1995","1996","1997","1998","1999","2000","2001","2002","2003","2004"/)
> month=(/"01","02","03","04","05","06","07","08","09","10","11","12"/)
> ndays=(/31,28,31,30,31,30,31,31,30,31,30,31/)
>
> nyear= dimsizes(year)
> nmon = dimsizes(month)
>
> paren = new((/nyear,nmon,nlat,nlon/), "float")
> sunshine = new((/nyear,nmon,nlat,nlon/), "float")
> alpha = new((/nyear,nlat,nlon/), "float")
> pot = new((/nyear,nmon,nlat,nlon/), "float")
>
>
> do i = 0, nyear - 1
> do j = 0, nmon - 1
>
> print("Getting data and preparing for " +year(i)+ " " +month(j)+ "
> and for paren alpha and sunshine duration")
>
> paren(i,j,:,:) =
> getPrecip("ENSMEAN_Pre_paren_"+year(i)+"_"+month(j)+".nc","t2m")
> printVarSummary(paren(i,j,:,:))
>
> sunshine(i,j,:,:) =
> getPrecip1("ENSMEAN_Pre_sund_"+year(i)+"_"+month(j)+".nc","sund")
> printVarSummary(sunshine(i,j,:,:))
>
> alpha(i,:,:) = getPrecip("ENSMEAN_Pre_alpha_"+year(i)+".nc","t2m")
> printVarSummary(alpha(i,:,:))
>
> print("Now taking potential evapotranspiration for " +year(i)+"
> "+month(j)+ " and for paren alpha and sunshine duration")
>
> pot(i,j,:,:) =
> 16*((paren(i,j,:,:))^(alpha(i,:,:)))*((sunshine(i,j,:,:))/12)*((ndays(j))/30)
> copy_VarCoords(paren(i,j,:,:),pot(i,j,:,:))
> printVarSummary(pot(i,j,:,:))
>
> ;*******************************************************************************
> ; Creating NetCDF files for writing and put time UNLIMITED
> ;*******************************************************************************
> print("Creating file
>ENSMEAN_Pre_pot_evap_"+year(i)+"_"+month(j)+".nc")
>
> system("/bin/rm -f
> ENSMEAN_Pre_pot_evap_"+year(i)+"_"+month(j)+".nc") ; remove any
> pre-existing file
> pot_evap =
> addfile("ENSMEAN_Pre_pot_evap_"+year(i)+"_"+month(j)+".nc","c") ;
> open output netCDF file
>
>
> ; make time and UNLIMITED dimension ; recommended for most
>applications
> filedimdef(pot_evap,"time",-1,True)
>
> ;************************************************************************************************************
> ; Writing down in the NetCDF files
> ;************************************************************************************************************
>
> ; output variables directly
> print("Writing down pet in
> ENSMEAN_Pre_pot_evap_"+year(i)+"_"+month(j)+".nc")
>
> pot!2 = "latitude" ; assign named
>dimensions
> pot!3 = "longitude"
>
> pot&latitude = refparam&latitude
> pot&longitude = refparam&longitude
>
> pot@long_name = "Potential Evap" ; assign attributes
> pot@units = "mm/month"
> pot_evap->pet = pot
>
> end do
> end do
>
> end
> ----------------------------------------------------------------------------------------------------------------
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Received on Mon Jan 27 06:44:43 2014