def dist(self, x1, x2):
        """Return the weighted distance between ``x1`` and ``x2``.

        Parameters
        ----------
        x1, x2 : `NumpyTensor`
            Tensors whose mutual distance is calculated.

        Returns
        -------
        dist : float
            The distance between the tensors.
        """
        if self.exponent == 2.0:
            return float(np.sqrt(self.const) * _norm_default(x1 - x2))
        elif self.exponent == float('inf'):
            return float(self.const * _pnorm_default(x1 - x2, self.exponent))
        else:
            return float((self.const ** (1 / self.exponent) *
                          _pnorm_default(x1 - x2, self.exponent)))