26.05.2016 16:16, BISSELL, Stephen (AEROCONSEIL SA) пишет:
Is there any roadmap within HDF5 to implement / define a portable time
type? H5T_TIME is clearly not portable, and from python forum reports I
see that python, at least, regards HDF5 as lacking a basic time type.
Alternatively, is there a wide-spread “de facto” that most people are
using to represent time – e.g. double?
To be clear, I’m referring to a no-frills “seconds since start of epoch”
type of time with resolution down to (at least) microseconds, which
would be used for “timestamping” data. Given the user base that HDF5
supports, this problem must have come up many times, with more demanding
sub-second resolution.
Currently, we use a composite, but this means that the time field always
has to be treated in a “special” way, which is unsatisfactory. And at
the most trivial level, HDFView allows a quick sanity check of data by
plotting one column against another as abscissa …. except in the case of
our composite time, where I’m limited to plotting against the seconds
part of the structure.
Hello Stephen!
It seems that perfect universal date/time format doesn't exist. Based on
application, ISO8601 or Unix time might be most appropriate. A good
example of how date/time might be handled is SQLite:
https://www.sqlite.org/datatype3.html#section_2_2
My personal experience suggests that ISO8601 is best (but only if
performance is not critical).
Best wishes,
Andrey Paramonov
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