numpy矩阵与向量类型的向量乘法

c = a*b

c
Out[66]: matrix([[ 6.830482]])

b
Out[80]:
array([[ 1.],
[ 1.],
[ 1.]])

a
Out[81]: array([1, 2, 3])

a*b
Out[82]:
array([[ 1.,  2.,  3.],
[ 1.,  2.,  3.],
[ 1.,  2.,  3.]])

b*a
Out[83]:
array([[ 1.,  2.,  3.],
[ 1.,  2.,  3.],
[ 1.,  2.,  3.]])

a
Out[84]: array([1, 2, 3])

b
Out[85]:
array([[ 1.],
[ 1.],
[ 1.]])

np.dot(a,b)
Out[86]: array([ 6.])

np.dot(b,a)
Traceback (most recent call last):

File "<ipython-input-87-919b2ab6633f>", line 1, in <module>
np.dot(b,a)

ValueError: shapes (3,1) and (3,) not aligned: 1 (dim 1) != 3 (dim 0)

a = np.array([[1],[2],[3]])

np.dot(b,a)
Traceback (most recent call last):

File "<ipython-input-89-919b2ab6633f>", line 1, in <module>
np.dot(b,a)

ValueError: shapes (3,1) and (3,1) not aligned: 1 (dim 1) != 3 (dim 0)