Dear Rosalyn,
Thanks very much for this update. I was wondering if it might be
helpful to clarify on this page the aspects of CF that the checker
cannot (or does not) check? For example, if a data provider does not
set the _FillValue correctly, this cannot be checked automatically
because the checker would have no way of knowing in advance which
cells should be marked in this way. Such a data file would be parsed
incorrectly by tools.
(This is a real example by the way - people often send me data files
that have been checked using the checker but still have problems -
presumably because the checker can, generally speaking, only check
syntax, not semantics.)
Best wishes,
Jon
P.S. In the case of _FillValue I guess you could apply a non-exact
method: if "a lot" of cells in a file have exactly the same value then
there's a fair chance this is supposed to be a _FillValue - perhaps
this information could be used to raise a warning to the user, even if
it's not enough to spot an error with certainty?
2009/1/19 Rosalyn Hatcher <r.s.hatcher at reading.ac.uk>:
> Dear All,
>
> I have updated the CF checker at
> http://puma.nerc.ac.uk/cgi-bin/cf-checker.pl to implement checks for CF-1.4
> as detailed in Trac Ticket #43 (One of the cell_methods recommendations has
> yet to be implemented as it's a bit more complex, but I hope to get around
> to that soon.)
>
> I have tested the changes on a very limited set of netcdf files that I've
> cobbled together from examples in the CF Document. If anyone has any CF-1.4
> compliant netcdf files I would be grateful if you could send me a few.
>
> If you find any problems please let me know. Assuming all is well I'll
> arrange for the version on the BADC site to be upgraded next week.
>
> Regards,
> Ros.
>
> --
> ------------------------------------------------------------------------
> Rosalyn Hatcher
> NCAS Computational Modelling Services
> Dept. of Meteorology, University of Reading, Earley Gate, Reading. RG6 6BB
> Email: r.s.hatcher at reading.ac.uk Tel: +44 (0) 118 378 6016
>
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
--
Dr Jon Blower
Technical Director, Reading e-Science Centre
Environmental Systems Science Centre
University of Reading
Harry Pitt Building, 3 Earley Gate
Reading RG6 6AL. UK
Tel: +44 (0)118 378 5213
Fax: +44 (0)118 378 6413
j.d.blower at reading.ac.uk
http://www.nerc-essc.ac.uk/People/Staff/Blower_J.htm
Received on Mon Jan 19 2009 - 03:36:15 GMT
