circumcenter.py

import numpy as np


def circumcenter(vert1, vert2, vert3):
    # H/T: wikipedia.org/wiki/Circumscribed_circle
    Ax, Ay = vert1
    Bx, By = vert2
    Cx, Cy = vert3

    D = 2 * (Ax * (By - Cy) + Bx * (Cy - Ay) + Cx * (Ay - By))
    norm_A = Ax**2 + Ay**2
    norm_B = Bx**2 + By**2
    norm_C = Cx**2 + Cy**2

    Ux = norm_A * (By - Cy) + norm_B * (Cy - Ay) + norm_C * (Ay - By)
    Uy = -(norm_A * (Bx - Cx) + norm_B * (Cx - Ax) + norm_C * (Ax - Bx))
    return np.array([Ux, Uy]) / D