Return a ditionary mapping time slide IDs to offset
		dictionaries.

def as_dict(self):
		"""
		Return a ditionary mapping time slide IDs to offset
		dictionaries.
		"""
		return dict((ilwd.ilwdchar(id), offsetvector.offsetvector((instrument, offset) for id, instrument, offset in values)) for id, values in itertools.groupby(self.cursor.execute("SELECT time_slide_id, instrument, offset FROM time_slide ORDER BY time_slide_id"), lambda (id, instrument, offset): id))