irfpy.asperacommon.dd

DD module. DD is developed by CESR.

DD module provides some useful functions related to DD.

irfpy.asperacommon.dd.ncdfdd2datetime(ddtime)[source]

Convert DD time that is read from NCDF file to datetime instance.

When DD time is read from NCDF file, it is in numpy array with single char.

The equivalent time format can be made as follows.

>>> import numpy
>>> t = numpy.array(['2', '0', '0', '9', '3', '6', '4', '1', '9', '2', '4', '0', '2',
...             '3', '6', '7', ''],
...             dtype='|S1')

In this case, the datetime object can be get as follows.

>>> print(ncdfdd2datetime(t))
2009-12-31 19:24:02.367000
irfpy.asperacommon.dd.ddtime2datetime(ddtime)[source]

Convert DD time to datetime instance.

Parameters

ddtime – DD time. 16 length string.

Note that the DD time’s DOY starts from 0, i.e. January 1st is DD DOY=0.

>>> t0 = ddtime2datetime('2009000000000000')
>>> print(t0.strftime('%F'))
2009-01-01

>>> t0 = ddtime2datetime('2009001125308444')
>>> print(t0.strftime('%FT%T.%f'))
2009-01-02T12:53:08.444000

>>> t0 = ddtime2datetime('2008140123456789')  # Check for leap year.
>>> print(t0.strftime('%FT%T.%f'))
2008-05-20T12:34:56.789000

>>> t0 = ddtime2datetime('2009140123456789')
>>> print(t0.strftime('%FT%T.%f'))
2009-05-21T12:34:56.789000

In DD’s netcdf file, the returned value is ndarray instance. Simplest way of converting is using ncdfdd2datetime().

If the length is >16, the first 16 characters are only used.

If shorter input comes, None is returned.

>>> t0 = ddtime2datetime('')
>>> print(t0)
None

>>> t0 = ddtime2datetime('2009141133')
>>> print(t0)
None

>>> t0 = ddtime2datetime('20XX140123456790')
>>> print(t0)
None