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[netCDF #MYT-239963]: info netcdf files

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  • Subject: [netCDF #MYT-239963]: info netcdf files
  • Date: Fri, 08 Oct 2010 10:48:03 -0600
Hi Yoann,

> I am dealing with netcdf ostia SST global product, and since the data are
> consuming a lot of space in my hard drive,
> I was wondering how to extract of the global file just the portion of
> territory which I am interested in.
> I amusing Matlab and SNC TOOL and MEXNC tools.
> but I just can t find the way to do that with this tools. So I am open to
> other tools if they are more efficient or whatever.
> could you please help me, if you know a solution;

The NCO software, and in particular the ncks utility, is useful for extracting
subsets of a netCDF data file and writing a new file containing just the subset.
See:

  http://www.unidata.ucar.edu/software/netcdf/software.html#NCO

for a description and links to NCO software.  Note that NCO is not developed or
supported by Unidata, so if you have questions, you will need to use the
sourceforge support forum for NCO.

Other utilities that may also be useful for the problem you describe include
NCL and CDO, described here:

  http://www.unidata.ucar.edu/software/netcdf/software.html#NCL
  http://www.unidata.ucar.edu/software/netcdf/software.html#CDO

If the data you are using is available remotely on a server via the OPeNDAP
protocols, then you can access just a single variable, such as SST, from the
file by using a URL instead of the filename to open the file, appending
"?SST" to the URL to just access the variable named "SST".  If the data is
available from a TDS server, you can use the experimental netCDF subset
service to access just the part of the grid within a specified latitude-
longitude bounding box, as described here:

  
http://www.unidata.ucar.edu/projects/THREDDS/tech/interfaceSpec/NetcdfSubsetService.html

Services provide with other servers, for example FERRET or GDS, can provide
a similar service:

  http://www.unidata.ucar.edu/software/netcdf/software.html#FERRET
  http://grads.iges.org/grads/gds/index.html

Finally, you can write a program that uses the netCDF library to read the
data file and write a new data file containing only the subset in which you 
are interested.  MATLAB supports use of the netCDF Java interface, which can
be used for such programs, as described here:

  http://sourceforge.net/apps/trac/njtbx

--Russ


--Russ


--Russ


--Russ

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



Ticket Details
===================
Ticket ID: MYT-239963
Department: Support netCDF
Priority: Normal
Status: Closed