>>> np.zeros(3)
array([0., 0., 0.])
>>> np.zeros((3,3))
array([[0., 0., 0.],
       [0., 0., 0.],
       [0., 0., 0.]])
>>> np.zeros((3,2))
array([[0., 0.],
       [0., 0.],
       [0., 0.]])
>>> np.eye(3)
array([[1., 0., 0.],
       [0., 1., 0.],
       [0., 0., 1.]])
>>> np.eye(3,2)
array([[1., 0.],
       [0., 1.],
       [0., 0.]])
>>> np.ones(3)
array([1., 1., 1.])
>>> np.ones((3,2))
array([[1., 1.],
       [1., 1.],
       [1., 1.]])
>>> np.diag([-2,3,1])
array([[-2,  0,  0],
       [ 0,  3,  0],
       [ 0,  0,  1]])
>>> np.diag([-2,3,1],1)
array([[ 0, -2,  0,  0],
       [ 0,  0,  3,  0],
       [ 0,  0,  0,  1],
       [ 0,  0,  0,  0]])
>>> np.diag([-2,3,1],-2)
array([[ 0,  0,  0,  0,  0],
       [ 0,  0,  0,  0,  0],
       [-2,  0,  0,  0,  0],
       [ 0,  3,  0,  0,  0],
       [ 0,  0,  1,  0,  0]])
>>> np.random.rand(5)
array([0.5704163 , 0.46493989, 0.85085904, 0.56177765, 0.06711559])
>>> np.random.rand(5,2)
array([[0.69873188, 0.66611399],
       [0.76550507, 0.25193332],
       [0.28569524, 0.67081913],
       [0.63928606, 0.97949063],
       [0.30312998, 0.31526063]])