def __init__(self, x=None, y=None, z=None):
        if x is None and y is None and z is None:
            self._pos3d = Vector(0, 0, 1)
        elif x is not None and y is not None and z is None:
            self._pos3d = Vector(x, y, math.sqrt(1 - y ** 2 - x ** 2))
        elif x is not None and y is not None and z is not None:
            self._pos3d = Vector(x, y, z).normalized()
        else:
            raise RuntimeError('invalid parameters')
dataset/ETHPy150Open scot-dev/scot/scot/eegtopo/geo_spherical.py/Point.__init__/swapped operands of `-`