Returns a resampled DataFrame

		Parameters
		----------
			rule : str
				the offset string or object representing target conversion
				for all aliases available see http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases
			how : str or dict
				states the form in which the resampling will be done.
				Examples:
					how={'volume':'sum'}
					how='count'
			df : DataFrame
				If omitted then the QuantFigure.DataFrame is resampled.
			kwargs
				For more information see http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.resample.html

def _get_resampled(self,rule,how={'ohlc':'last','volume':'sum'},df=None,**kwargs):
		"""
		Returns a resampled DataFrame

		Parameters
		----------
			rule : str
				the offset string or object representing target conversion
				for all aliases available see http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases
			how : str or dict
				states the form in which the resampling will be done.
				Examples:
					how={'volume':'sum'}
					how='count'
			df : DataFrame
				If omitted then the QuantFigure.DataFrame is resampled.
			kwargs
				For more information see http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.resample.html

		"""
		df=self.df.copy() if df is None else df
		if rule==None:
			return df 
		else:
			if isinstance(how,dict):
				if 'ohlc' in how:
					v=how.pop('ohlc')
					for _ in ['open','high','low','close']: 
						how[_]=v
				_how=how.copy()
				for _ in _how:
					if _ not in self._d:
						del how[_]
			return df.resample(rule=rule,**kwargs).apply(how)