Generate Spirograph dots with numpy.

def give_dots(R, r, r_, resolution=2*PI/1000, spins=50):
    '''Generate Spirograph dots with numpy.
    '''
    thetas = np.arange(0, 2*PI*spins, resolution)
    Rr = R - r
    x = Rr * np.cos(thetas) + r_*np.cos(Rr / r * thetas)
    y = Rr * np.sin(thetas) - r_*np.sin(Rr / r * thetas)
    return x, y