importnumpyasnpimportmatplotlib.pyplotaspltD=np.array([[2,.3],[.3,2.5]])# creating an ellipse)lam,vec=np.linalg.eigh(D)theta=np.linspace(-np.pi,np.pi,1001)xy=np.stack((lam[0]*np.cos(theta),lam[1]*np.sin(theta)),axis=0)xy=vec.T@xyradii=np.sqrt(np.sum(xy**2,axis=0))thetas=np.arctan2(-xy[1],xy[0])plt.figure()# with ticksax1=plt.subplot(121,projection='polar')ax1.plot(thetas,radii)# without ticksax2=plt.subplot(122,projection='polar')ax2.plot(thetas,radii)ax2.set_yticks([])ax2.set_xticks([])plt.show()