def normalize(self,asOf=None,multiplier=100):
	"""
	Returns a normalized series or DataFrame
	
	Example:
		Series.normalize()

	Returns: series of DataFrame
	
	Parameters:
	-----------
		asOf : string
			Date format
			'2015-02-29'
		multiplier : int
			Factor by which the results will be adjusted
	"""
	if not asOf:
		x0=self.iloc[0]
	else:
		x0=self.loc[asOf]
	return self/x0*multiplier