How to handle time in irfpy

Introduction

A general way for python to handle the time is using datetime module. datetime.datetime class provide various way (including localtime) of handling the time.

There are three typical way of expressing time in irfpy.

  • datetime.datetime class object

  • Floating epoch time (POSIX type)

  • Julday object

In addition, there are fourth commonly used time definition, i.e. matplotlib time. This is an offset of Julian day by (TBC) and very similar to Matlab time. This is not implemented in this version of irfpy, but obviously in a near future scope.

utc module

utc module mainly provides the conversion among the above defined time format.

>>> import datetime
>>> t = datetime.datetime(2010, 12, 19, 14, 23, 27)
>>> print t
2010-12-19 14:23:27

Only datetime without localtime zone is supported.

The time t can be converted by utc.convert function. First argument is the time and the second (indeed this is outfmt keyword) is the format to be converted. Default is float.

>>> from irfpy.util import utc
>>> t_float = utc.convert(t)
>>> print t_float
1292768607.0

>>> from irfpy.util import julday
>>> t_julday = utc.convert(t, julday.Julday)
>>> print t_julday
Julday(2010, 12, 19, 14, 23, 27.000)