def test_horizontalAndVerticalSet(self):
        """
        The PDOP is correctly determined from HDOP and VDOP.
        """
        hdop, vdop = 1.0, 1.0
        pdop = (hdop**2 + vdop**2)**.5
        pe = base.PositionError(hdop=hdop, vdop=vdop)
        self._testDOP(pe, pdop, hdop, vdop)

        The PDOP is correctly determined from HDOP and VDOP.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/positioning/test/test_base.py