sidereal.py: Internal maintenance specification

This is a convenience function that returns the hour angle for a specific time utc and longitude eLong.

# - - -   R A D e c . h o u r A n g l e

    def hourAngle ( self, utc, eLong ):
        """Find the hour angle at a given observer's location.

          [ (utc is a Universal Time as a datetime.datetime) and
            (eLong is an east longitude in radians) ->
              return the hour angle of self at that time and
              longitude, in radians ]
        """

The work is passed along to the standalone function Section 9.4, “raToHourAngle(): Convert a right ascension to an hour angle”.

        return  raToHourAngle ( self.ra, utc, eLong )