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 <[email protected]> > 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 <[email protected]> > CC: "[email protected]" <[email protected]> > 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<[email protected]> > >>User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.5; rv:10.0.2) > >> Gecko/20120216 Thunderbird/10.0.2 > >>To: [email protected] > >>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: [email protected] > >>>_______________________________________________ > >>>CF-metadata mailing list > >>>[email protected] > >>>http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > >>_______________________________________________ > >>CF-metadata mailing list > >>[email protected] > >>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: [email protected] -- 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: [email protected] _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
