def __init__(self, a, b, c=None):
        if c is None:
            self.c = Point.fromvector(a.vector)     # Center
            self.x = Point.fromvector(b.vector)     # a point on the circle
        else:
            self.c = Point.fromvector((a.vector - b.vector).cross(c.vector - b.vector).normalized())    # Center
            self.x = Point.fromvector(b.vector)     # a point on the circle
dataset/ETHPy150Open scot-dev/scot/scot/eegtopo/geo_spherical.py/Circle.__init__/swapped operands of `-`