def METHOD_NAME(x,y):
    y1 = y[:-1]
    y2 = y[1:]
    x1 = x[:-1]
    x2 = x[1:]
    xy = (x1*y2 - x2*y1)
    Cx = np.sum((x1+x2)*xy)/6.
    Cy = np.sum((y1+y2)*xy)/6.
    A = 0.5*np.sum(xy)
    return Cx/A, Cy/A