def freq(self, x=None):
""" Number of data items per year. If data does not contain
datetime index, assume daily frequency with 252 trading days a year."""
x = x or self.r
return tools.freq(x.index)
def freq(self, x=None):
""" Number of data items per year. If data does not contain
datetime index, assume daily frequency with 252 trading days a year."""
x = x or self.r
return tools.freq(x.index)