Re: [netcdfgroup] NetCDF4 for Fusion Data

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Re: [netcdfgroup] NetCDF4 for Fusion Data
• From: John Storrs <john.storrs@xxxxxxxxxxxx>
• Date: Tue, 27 Jan 2009 19:15:01 +0000

I see that coordinate variable data is stored in HDF5 dimension scale
datasets, and that each ordinary variable is bound to one or more of these
datasets through the HDF5 dimension scale mechanism. Evidently netCDF-4
variables are aware of both their named dimensions (expected) and any
associated coordinates (unexpected). The netCDF documents state that
coordinate variables  are a convention, and 'have no special meaning to the
netCDF library'. But evidently the association is fully defined at storage
level in netCDF-4/HDF5 files. Is there an API to access this useful
information? Apologies if I'm missing something here.

Also the scope of the dimension to coordinate variable association isn't clear
to me - I haven't found anything to explain it. I'm picturing a tree of
groups with dimensions and coordinate variables in various places in it,
perhaps with duplicate naming (eg repetition of a subtree). What is the
scoping rule?

Regards
John

--
John Storrs, Experiments Dept      e-mail: john.storrs@xxxxxxxxxxxx
Building D3, UKAEA Fusion                               tel: 01235 466338
Culham Science Centre                                    fax: 01235 466379
Abingdon, Oxfordshire OX14 3DB              http://www.fusion.org.uk

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  • [netcdfgroup] NetCDF4 for Fusion Data
    • From: John Storrs