def _calculate_z_values(self):
    'Calculate z statistics for our two sets of coefficients\n        '
    (_std_error0, _std_error1) = self._calculate_robust_standard_errors()
    _z_values0 = (self.lambda_0_coefficients[:, 0] / _std_error0)
    _z_values1 = (self.lambda_1_coefficients[:, 0] / _std_error1)
    return (_z_values0, _z_values1)
Calculate z statistics for our two sets of coefficients
def _calculate_z_values(self):
    '\n        '
    (_std_error0, _std_error1) = self._calculate_robust_standard_errors()
    _z_values0 = (self.lambda_0_coefficients[:, 0] / _std_error0)
    _z_values1 = (self.lambda_1_coefficients[:, 0] / _std_error1)
    return (_z_values0, _z_values1)