Richard,
Very well put!
> However you choose to peer into your netCDF files you are seeing them
> through the lens of a "client library".
This is a very good point -- indeed, even if we use a text
representation of dates, that's really still binary on disk, though
with a well-known encoding (ascii/unicode, or ??/)
So there is, by definition, no human-readable encoding available!
> But if the library can't do machine-to-human then it probably
> can't do human-to-machine. In which case there's very little you can
> actually _do_ with the date/time values (e.g. determine ordering or compute
> intervals).
Bingo!
Indeed, for "real" use cases, human readability really is worthless --
most data sets are far too big to do anything useful with the data by
hand anyway.
John Caron wrote:
> An insidious mistake is to think that problems should be fixed in software libraries.
Fair enough, but I'm not sure we have a "problem" here at all. And
indeed, it way be just as insidious to think that problems can be
solved with some nifty new addition to an existing data standard.
1) I agree with Steve that we aren't in a position at this point to
decide what the best encoding of datetime is -- rather, we are
deciding if adding another encoding is a good idea. Unless someone is
suggesting deprecating the old one.
2) I'm also not at all sure that string representations are a better
way to go -- netcdf is primarily for consumption by computer programs
-- and the existing encoding is a pretty natural fit for that.
3) I don't see how datetime strings "solve" the calendar problem --
sure, it's clear what calendar data the provider intended, but if you
want to know how much time passed between two dates, you're back to
the same problem (I just noticed that you pointed that out) -- I
actually think time deltas are often more important that absolute
times anyway.
> Finish your beer and ill order another round.
I'll get the round after that -- it take a few!
John Graybeal wrote:
> (Note that among those users are people who look at binary dumps of files, of which I am one but I'm sure there are many others.)
binary dumps? in hex? and ISO strings are somehow readable there? huh?
(ncdump, which I use often is not a binary dump, it's ascii dump (does
it support any other text encoding?), and already handles the
conversion to iso strings (in recent versions, anyway).
By the way, no objection to the standard name -- none at all.
-Chris
--
Christopher Barker, Ph.D.
Oceanographer
Emergency Response Division
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Chris.Barker at noaa.gov
Received on Tue Mar 19 2013 - 17:26:35 GMT
