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[netCDF #BEG-121909]: Filling Missing Values

Hi Mack,

Sorry to have taken so long to respond to your question.
> My name is Mack Jones and I was referred to ask this question to you by Jeff
> Weber.  I am a graduate over at CU (ex-SOARS protege) and am working with
> data from MERRA Reanalysis.  Now output files are in netcdf format and I have
> been using the ncea command to perform grid point averages of these.  First I
> wanted to make sure I was using the right command to average each on of these
> files over time.  For each file there are 8 times steps so I am trying to 
> average
> each the same grid point at say hour 3 for 20 files or so.  The command I have
> been using is ncea -v ..... MERRA* -o ......  Is this the correct command?

I'm not much of an expert on the NCO utilites, which is where ncea comes from.
From what you've described, ncea sounds right, but ncra might be more 
appropriate
if the variables you are averaging are defined with an unlimited (record) 
dimension.

> Here comes where I having the problem.  Before I do the ncea command I want
> to remove the missing values and replace them with zeros.  Now I have read 
> that
> nco package has a _fillvalues and missing_value command.  How would you
> suggest best handling this problem?

I think ncea is supposed to automatically leave fill values out of the average,
so if that's what you want, you shouldn't have to replace them with zeros.
Replacing the values with zeros might compute the wrong average, just as the 
average of {1, 2, 3} is 2, but the average of {1, 0, 2, 0, 3, 0} is 1.  If I
have misunderstoood what you want to do, then I recommend seeking help from
the NCO support forums, by posting your questions to this NCO help site:

  http://sourceforge.net/projects/nco/forums/forum/9830

--Russ

Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: BEG-121909
Department: Support netCDF
Priority: Normal
Status: Closed