Returns a DataFrame with the required format for 
	a scatter (lines) plot

	Parameters:
	-----------
		n_traces : int
			Number of traces 
		n : int
			Number of points for each trace
		columns : [str]
			List of column names
		dateIndex : bool
			If True it will return a datetime index
			if False it will return a enumerated index
		mode : string
			Format for each item
				'abc' for alphabet columns
				'stocks' for random stock names

def lines(n_traces=5,n=100,columns=None,dateIndex=True,mode=None):
	"""
	Returns a DataFrame with the required format for 
	a scatter (lines) plot

	Parameters:
	-----------
		n_traces : int
			Number of traces 
		n : int
			Number of points for each trace
		columns : [str]
			List of column names
		dateIndex : bool
			If True it will return a datetime index
			if False it will return a enumerated index
		mode : string
			Format for each item
				'abc' for alphabet columns
				'stocks' for random stock names
	"""	
	index=pd.date_range('1/1/15',periods=n) if dateIndex else list(range(n))
	df=pd.DataFrame(np.random.randn(n,n_traces),index=index,
		columns=getName(n_traces,columns=columns,mode=mode))
	return df.cumsum()