Re: more on netCDF 4 compatibility requirements...

Hi Ed,
    Here's a short list of features that HDF5 will have to provide in
order to allow netCDF objects to be stored correctly:
    - Dimension Scales for dataspaces
    - Shared dimension scales and/or dataspaces for datasets

    Is there anything else that will be needed in HDF5 for netCDF support?

        Quincey Koziol
        HDF5 Development Team
        NCSA

> Here's some more detail on what we expect netCDF 4 to be able to
> do. Please let me know what you think...
> 
> 
> * NetCDF File Format Compatability
> 
> ** NetCDF 4 uses HDF5 as it's storage layer.
> 
> ** NetCDF 4 can also create/read/modify files created with previous
>    versions of netCDF, using the original netCDF data format.
> 
> ** If the user opens an old netCDF file, and attempts to modify it,
>    NetCDF 4 will stick with the (old) netCDF file format. New API
>    features (like bit-packing) won't work on these files.
> 
> ** There will be a way for users to cause an old netCDF file to be
>    copied into the new HDF5 data format.
> 
> ** NetCDF 4 can read files created with HDF5, but some features will be
>    inaccessible (rasters, for example). Certain group conventions may
>    be required for a HDF5 file to be accessible via netCDF.
> 
> ** NetCDF 4 can't read HDF 4 files.
> 
> ** NetCDF 4 has no knowledge of HDF-EOS.
> 
> 
> 
> * NetCDF API Backward Compatibility
> 
> ** Interface will be added to, but all existing function calls will
>    remain the same, so that programs written for netCDF 3.x will work
>    for netCDF 4.0 with a simple compile.
> 
> ** By default, the netCDF 4 API creates HDF5 files. A renamed set of
>    functions allows access to the original 3.x netCDF functions, which
>    allow the users to create netCDF format files.
> 

>From owner-netcdf-hdf@xxxxxxxxxxxxxxxx 09 2003 Jul -0600 11:35:41 
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Date: 09 Jul 2003 11:35:41 -0600
From: Edward Hartnett <ed@xxxxxxxxxxxxxxxx>
In-Reply-To: <200307091726.h69HQwPE035773@xxxxxxxxxxxxxxxxxxxxxx>
To: Quincey Koziol <koziol@xxxxxxxxxxxxx>
Subject: Re: more on netCDF 4 compatibility requirements...
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Quincey Koziol <koziol@xxxxxxxxxxxxx> writes:

> Hi Ed,
>     Here's a short list of features that HDF5 will have to provide in
> order to allow netCDF objects to be stored correctly:
>     - Dimension Scales for dataspaces
>     - Shared dimension scales and/or dataspaces for datasets
> 
>     Is there anything else that will be needed in HDF5 for netCDF support?

I sure don't know the answer to that one yet!

Ed
>From owner-netcdf-hdf@xxxxxxxxxxxxxxxx 09 2003 Jul -0600 11:38:14 
Message-ID: <wrx8yr77g8p.fsf@xxxxxxxxxxxxxxxxxxxxxxx>
Date: 09 Jul 2003 11:38:14 -0600
From: Edward Hartnett <ed@xxxxxxxxxxxxxxxx>
In-Reply-To: <200307091726.h69HQwPE035773@xxxxxxxxxxxxxxxxxxxxxx>
To: netcdf-hdf@xxxxxxxxxxxxxxxx
Subject: netcdf 4 web page, with updated feature list...
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Howdy again!

Russ had a bunch of suggestions for the netcdf-4 feature list, which
have all been incorporated into the document.

It's now also posted on a web server, so that we can all see it more
easily. Take a look at
http://dev.unidata.ucar.edu/content/software/netcdf-4/index.html 

Thanks,

Ed
>From owner-netcdf-hdf@xxxxxxxxxxxxxxxx 09 2003 Jul -0600 14:13:18 
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Date: 09 Jul 2003 14:13:18 -0600
From: Edward Hartnett <ed@xxxxxxxxxxxxxxxx>
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To: netcdf-hdf@xxxxxxxxxxxxxxxx
Subject: Re: netcdf 4 web page, with updated feature list...
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Edward Hartnett <ed@xxxxxxxxxxxxxxxx> writes:

Woops, I gave out a URL that will only work within Unidata. For those
who are elsewhere, here's the URL to use:

http://my.unidata.ucar.edu/content/software/netcdf-4/index.html 

Thanks,

Ed