Re: gives warning that dimension already exists

Donna Cote wrote:
> Dennis, I see your point about choosing to replace a variable vs adding
> one, but one of my goals is to avoid using any NCO operators.
>
> Am I not allowed to *replace* the "char Times(Time, DateStrLen) ;"
> variable with a
> double Times(Time) ;
> Times:units = "hours since 2001-06-11 12:00:00" ;
> Times:long_name = "Time" ;
> Times:description = "Time" ;
> (Time Coordinate) variable?

No.

Just to be clear, the variable

char Times(Time, DateStrLen)

would remain on the file. Note that the variable
name is "Times" ... with an 's' at the end.
The name of the dimension is "Time" ... no 's'

You must add the Time(Time).

There is *no harm* in having both Times and Time on the file.
The file would still be CF conformant.
>
> Is there a function of the form of GetVar which would accomplish a merge
> (instead of using the ncrcat or ncks operator)? I imagine I would have
> to use GetVar (not sure of the name) on each and every variable that I
> want to merge in. For my first goal, which is to get just the V10,U10
> and slp variables from WRF to a Time Coordinate format, copying over
> these few variables would be trivial.
>
> Maybe, starting with this small example, you could help me find a way to
> have NCL do all the work?
>
> Thanks
> Donna
>
> Dennis Shea wrote:
>> I don't think you can not use the "w" on the addfile line.
>>
>> This is for replacing values of an *existing* variable.
>> EG: Say you want to change temperature from C to K.
>> No new space is needed on the file. The new values just overwrite
>> the old values.
>>
>> You want to *add* a new variable. Something like
>>
>> netcdf WRF.CF {
>> dimensions:
>> Time = UNLIMITED ; // (25 currently)
>> DateStrLen = 19 ;
>> bottom_top = 27 ; south_north = 81 ;
>> west_east = 90 ;
>> variables:
>> double Time(Time) ;
>> Time:units = "hours since 2001-06-11 12:00:00" ;
>> Time:long_name = "Time" ;
>> Time:description = "Time" ;
>> char Times(Time, DateStrLen) ;
>>
>> where The Time(Time) has been added.
>>
>> A suggested way of doing this:
>>
>> [1] Use NCL to read the character variable 'Times'
>> [2] Use
>> http://www.ncl.ucar.edu/Document/Functions/WRF_contributed/wrf_times_c.shtml
>>
>> to create the numeric variable Time(Time)
>> [3] Create a file with just this variable on it.
>> [3] Use the netCDF operator ncks [, ncrcat] to merge
>> the two files.
>>
>> Good luck
>>
>>
>> Donna Cote wrote:
>>> The purpose of my little script is to read a WRF file
>>> (wrfout_d01...blah.blah.blah) and change the Time variable from
>>> character to a Time Coordinate var.
>>> I am reading in a file with the "w" option [ f=addfile(outname,"w") ]
>>>
>>> I am wondering if I need to "undefine" the Time dimension in order to
>>> replace it or change it.
>>>
>>> Thanks,
>>> Donna Cote
>>>
>>> <big snip>
>
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Received on Wed Nov 05 2008 - 13:27:31 MST