Hello Karl,
Ok - I'm with you. I'll implement your idea on matching global
attributes, thanks.
All the best,
David
---- Original message from Karl Taylor (01PM 19 Mar 12)
> Date: Mon, 19 Mar 2012 13:39:25 -0700
> From: Karl Taylor <taylor13 at llnl.gov>
> User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.5; rv:10.0.2)
> Gecko/20120216 Thunderbird/10.0.2
> To: David Hassell <d.c.hassell at reading.ac.uk>
> CC: "cf-metadata at cgd.ucar.edu" <cf-metadata at cgd.ucar.edu>
> Subject: Re: [CF-metadata] cf2cf - a new tool
>
> Hello David,
>
> I just noticed a typo in my email that might of confused some of
> you: I meant to say "*shouldn't* conflict between variables you
> want to aggregate" (otherwise it probably wouldn't make sense to
> aggregate them).
>
> Perhaps you should treat the standard CF global attributes like the
> non-standard ones and include only those that are identical across
> aggregated variables.
>
> best,
> Karl
>
>
>
> On 3/19/12 1:16 PM, David Hassell wrote:
> >Hello Karl,
> >
> >An astute point. I confess to sweeping this under the carpet a little
> >bit and ignoring (deleting) the standard CF global attributes as given
> >in appendix A, but insisting that non-standard ones are identical for
> >aggregated fields.
> >
> >This is an easy and pragmatic approach as a programmer, but probably
> >not the most useful one? For me, it raises issues such as whether or
> >not an attribute should be a scalar auxiliary coordinate, or could
> >perhaps be 'promoted' to be one during the aggregation. Or perhaps
> >such attributes should be concatenated? etc. This area is
> >deliberately not regulated in our CF aggregation rules - rather
> >leaving it to an implementation's, or the users, discretion, which can
> >vary with application.
> >
> >Since a tool should be useful to the users (not just easy for
> >programmers!), opinions are welcome.
> >
> >All the best,
> >
> >David
> >
> >---- Original message from Karl Taylor (10AM 19 Mar 12)
> >
> >>Date: Mon, 19 Mar 2012 10:51:36 -0700
> >>From: Karl Taylor<taylor13 at llnl.gov>
> >>User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.5; rv:10.0.2)
> >> Gecko/20120216 Thunderbird/10.0.2
> >>To: cf-metadata at cgd.ucar.edu
> >>Subject: Re: [CF-metadata] cf2cf - a new tool
> >>
> >>presumably this tool is limited to combining files with identical
> >>global attributes? Of course the global attributes should conflict
> >>between variables that you want to aggregate.
> >>
> >>Karl
> >>
> >>On 3/19/12 10:28 AM, David Hassell wrote:
> >>>Hello,
> >>>
> >>>I'd like to advertise a hopefully useful new tool called 'cf2cf' for
> >>>combining many CF-netCDF files into a single CF-netCDF file, where the
> >>>input fields are aggregated into as few multidimensional netCDF
> >>>variables as possible.
> >>>
> >>>This is a command line utility which utilizes the proposed CF
> >>>aggregation rules (trac ticket #78) to combine CF fields based on
> >>>their metadata. In particular differing variables' units, dimension
> >>>order, dimension direction and netCDF variable names are are accounted
> >>>for in the aggregation process.
> >>>
> >>>A quick, simple example:
> >>>
> >>>% cf2cf -o one_output_file.nc lots_of_input_files*.nc
> >>>
> >>>All details, including full documentation, more examples and
> >>>installation, may be found at
> >>>http://www.met.reading.ac.uk/~david/cf2cf.html
> >>>
> >>>This tool uses the python cf package
> >>>(http://code.google.com/p/cf-python), which also makes the same CF
> >>>aggregation and the CF data model (trac ticket #68) available in an
> >>>API, in a memory efficient manner.
> >>>
> >>>Any feedback, positive or negative, on cf2cf, the CF aggregation rules
> >>>and the cf python package would, of course, be most gratefully
> >>>received, to help make these better.
> >>>
> >>>All the best,
> >>>
> >>>David
> >>>
> >>>--
> >>>David Hassell
> >>>National Centre for Atmospheric Science (NCAS)
> >>>Department of Meteorology, University of Reading,
> >>>Earley Gate, PO Box 243,
> >>>Reading RG6 6BB, U.K.
> >>>
> >>>Tel : 0118 3785613
> >>>Fax : 0118 3788316
> >>>E-mail: d.c.hassell at reading.ac.uk
> >>>_______________________________________________
> >>>CF-metadata mailing list
> >>>CF-metadata at cgd.ucar.edu
> >>>http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >>_______________________________________________
> >>CF-metadata mailing list
> >>CF-metadata at cgd.ucar.edu
> >>http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >
> >
> >--
> >David Hassell
> >National Centre for Atmospheric Science (NCAS)
> >Department of Meteorology, University of Reading,
> >Earley Gate, PO Box 243,
> >Reading RG6 6BB, U.K.
> >
> >Tel : 0118 3785613
> >Fax : 0118 3788316
> >E-mail: d.c.hassell at reading.ac.uk
--
David Hassell
National Centre for Atmospheric Science (NCAS)
Department of Meteorology, University of Reading,
Earley Gate, PO Box 243,
Reading RG6 6BB, U.K.
Tel : 0118 3785613
Fax : 0118 3788316
E-mail: d.c.hassell at reading.ac.uk
Received on Tue Mar 20 2012 - 16:46:03 GMT
