[MITgcm-support] mnc questions

[Ed Hill]

On Fri, 2005-12-16 at 00:03 -0600, Michael Schaferkotter wrote:
> 
> the mnc_max_fsize should have been set to around 20MB. 

20MB = 1024*1024*20 bytes = 20971520 = (approx) 2.1*10^7


> i/m trying to get one set of variables per dump per .nc file.

Why?

I mean, whats the point of creating netCDF files that each contain just
one time step?  Its terribly wasteful.  You can always extract
individual time steps from a netCDF file containing many time steps
using the cool NCO tools:

  http://nco.sourceforge.net/

with syntax such as:

  ncks -d T,1,1  state.0000000000.t001.nc s2.nc
  ncks -d T,6,6  state.0000000000.t001.nc s7.nc

where the above commands pull out the 2nd and 7th time step of all
variables from the state file.  Neat, huh?  And very convenient.

And you can easily accomplish similar feats using many other tools.  For
instance, the MatLAB rdnctiles() program in:

  MITgcm/utils/matlab/gmt/rdnctiles.m

has some neat functionality and the CDO programs can also do a lot of
*very* helpful netCDF manipulation:

  http://www.mpimet.mpg.de/~cdo/

that isn't easily accomplished with the old-style "flat" binary files.

Ed

-- 
Edward H. Hill III, PhD
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