#NEWLINE# @ property #NEWLINE# def center( self ) : #NEWLINE# #INDENT# '\n        Return center frequencies :math:`f_c`.\n        \n        .. math::  f_c = f_{ref} \\cdot 2^{n/N} \\cdot 10^{\\frac{3}{10N}}\n        \n        ' #NEWLINE# n = self . n #NEWLINE# return self . _fc ( n )