Martin,
I'll answer on the mailing-list since I have no trac-account.
2) seems fine to me, since it's only an extension to netcdf4/CDM-2.
1) I've never had problems with the current set of rules, so some more
concrete examples where the current rules don't work might help persuade me.
And even your proposal is not completely clear: Do you really want to
have both 'standard_name' and 'axis', or would one be enough. Requiring
both 'axis = "X"' and 'standard_name = "projection_x_axis"' does not
look efficient.
Best regards,
Heiko
On 2012-07-06 16:07, Martin Schultz wrote:
#90: Collection of CF enhancements for interoperable applications
----------------------------+-----------------------------------------------
Reporter: mgschultz | Owner: [email protected]
Type: enhancement | Status: new
Priority: medium | Milestone:
Component: cf-conventions | Version:
Keywords: |
----------------------------+-----------------------------------------------
Dear all,
in an offline discussion with Jonathan and a few others, it became
apparent that there may be a few limitations in the current CF convention
which make life difficult for building true interoperable services. One of
the major obstacles at present is the optional character of attributes, in
particular for coordinate axes. If an application cannot rely on finding
some specific information about a coordinate, it becomes virtualyl
impossible to interpret this information correctly without human
intervention (or one has to start guessing which will almost certainly
fail at some point). According to my understanding, making attributes
mandatory could break the backward compatibility principle that CF has
hitherto held very high. Therefore, it appears appropriate to begin a
collection of issues about the current CF convention which impediment the
implementation of interoperability, and which would not be backward-
compatible. Depending on the outcome of this discussion (for which we
should allow some time), one could decide to either start a new CF major
version number, or adopt all incompatible changes in one new step release
version. It should be avoided to introduce incompatible changes in several
individual releases.
Here I begin with three items. Responses should indicate whether they
agree that these changes cause incompatibilities. If you want to add other
issues, please prepend an item number. If discussions on individual issues
get lengthy, we should open separate track tickets for them and feed the
conclusion back into this ticket.
1) make axis attribute and standard_name attribute mandatory for
coordinate variables
2) introduce a "group" level in order to be compatbile with the netcdf4
and hdf data model: each group can have its own coordinate system, but all
variables within a group must share the same coordinates
3) standardize use of comments where these are necessary to uniquely
identify what a standard_name means or what a variable contains. Examples
are the lumping of NMVOC compounds, where the definition of the lumped
group should be provided, or the newly proposed emission sectors
--
Dr. Heiko Klein Tel. + 47 22 96 32 58
Development Section / IT Department Fax. + 47 22 69 63 55
Norwegian Meteorological Institute http://www.met.no
P.O. Box 43 Blindern 0313 Oslo NORWAY
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