def twosided_gen(self):
for a in range(<NUM_LIT:0>, self.N):<EOL><INDENT>yield a * self.df<EOL><DEDENT>
Returns the twosided frequency range as a generator

        ::

            >>> print(list(Range(8).centerdc_gen()))
            [0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875]