Re: Variable (time) is undefined

Hi Mark

time is only a variable dimension name in wrfot_ file, like attribute. You can not just it while you read the variable.
If you want to read the whole variable, you can simply use T(:, :, :, :). If you want to use dimension name while reading the variable, you can use T(time|:, long|:, lat|:, level|:).

If you just want to extract some dimension of variable, you can use T(0:2, :, :, :).

Actually there is one variable in wrfout_ file, called “Times”, It has 2-Dimension. The first dimension is how many times you have in the wrfout_ file. The second dimension is the character length of “Times”, usually it has 19 characters. So that means Times’ dimension is like (:, 19).

For your case, you need to read out how many time you have in the wrfout_ file. Then you can specify which time you want to read out.

Thank you
Zhifeng (Bruce) Yang
Homepage : http://zyang01.com/

On Jan 18, 2014, at 12:30 PM, Mark Chan <cym263@yahoo.com> wrote:

> Dear NCL users,
>
> Below is a ncl script, which runs some errors.
>
> --------ncl script--------------------------
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> load "$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/shea_util.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRF_contributed.ncl"
>
> nc_file = systemfunc("ls -1 wrfout_d01_*") + ".nc"
> a = addfiles(nc_file,"r")
> T = nc_file->T(time,:,:,:)
> th = T + 300.
> P = nc_file->P(time,:,:,:)
> PB = nc_file->PB(time,:,:,:)
> p = ( P + PB )
> tk = wrf_tk( p , th )
> QVAPOR = nc_file->QVAPOR(time,:,:,:)
> PH = nc_file->PH(time,:,:,:)
> PHB = nc_file->PHB(time,:,:,:)
> var = ( PH + PHB ) / 9.81
> dim = dimsizes(var)
> z = 0.5 * ( var(0:dim(0)-2,:,:) + var(1:dim(0)-1,:,:) )
> slp = wrf_slp( z, tk, p, QVAPOR )
>
>
> The error messages are as in the below. Can one give a suggestion?
>
> Thanks a lot!
> Mark
>
> ============Error message==============================================
> Copyright (C) 1995-2013 - All Rights Reserved
> University Corporation for Atmospheric Research
> NCAR Command Language Version 6.1.2
> The use of this software is governed by a License Agreement.
> See http://www.ncl.ucar.edu/ for more details.
> fatal:Variable (time) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 12 in file slp3.ncl
>
> fatal:Variable (T) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 13 in file slp3.ncl
>
> fatal:Variable (time) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 15 in file slp3.ncl
>
> fatal:Variable (time) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 16 in file slp3.ncl
>
> fatal:Variable (P) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 17 in file slp3.ncl
>
> fatal:Variable (p) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 19 in file slp3.ncl
>
> fatal:Variable (time) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 21 in file slp3.ncl
>
> fatal:Variable (time) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 22 in file slp3.ncl
>
> fatal:Variable (time) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 23 in file slp3.ncl
>
> fatal:Variable (PH) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 24 in file slp3.ncl
>
> fatal:Variable (var) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 25 in file slp3.ncl
>
> fatal:Undefined identifier: (var) is undefined, can't continue
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 26 in file slp3.ncl
>
> fatal:Variable (z) is undefined
> fatal:["Execute.c":8128]:Execute: Error occurred at or near line 28 in file slp3.ncl
>
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Received on Sat Jan 18 12:13:04 2014