code: def add_atr(self,periods=14,str=None,name='',**kwargs):
  		
  		study={'kind':'atr',
  			   'name':name,
  			   'params':{'periods':periods,'high':self._d['high'],'low':self._d['low'],'close':self._d['close'],
  						 'str':str},
  			  'display':utils.merge_dict({'legendgroup':False},kwargs)}
  		self._add_study(study)
docs: Add Average True Range (ATR) study to QuantFigure.studies
  
  		Parameters:
  			periods : int or list(int)
  				Number of periods
  			name : string
  				Name given to the study
  			str : string
  				Label factory for studies
  				The following wildcards can be used:
  					{name} : Name of the column
  					{study} : Name of the study
  					{period} : Period used
  				Examples:
  					'study: {study} - period: {period}'
  		kwargs: 
  			legendgroup : bool
  				If true, all legend items are grouped into a 
  				single one
  			All formatting values available on iplot()