a4 = np.array([[3,0,3],[3,3,3],[0,3,3]])

det = np.linalg.det(a4)
print(det)

27.0

from mpl_toolkits.mplot3d import Axes3D

fig = plt.figure(figsize=(6,6))
ax = fig.gca(projection='3d')

origin = np.zeros(a4.shape) # origin point

ax.quiver(*origin, *a4)

plt.grid()
ax.set_zlim3d(-5, 5)
ax.set_ylim3d(-5, 5)
ax.set_xlim3d(-5, 5)  
plt.show()