ValueError：形状（1,1000）和（1,1000）不对齐：1000（dim 1）！= 1（dim 0）当numpy.dot（）具有两个矩阵时

Question

I am trying to multiply two matrices using numpy.dot() and they are the same dimensions. But when i try to do it numpy gives me the error in the title saying that they are not aligned which doesnt make sense to me because they are the same dimensions. Could anyone explain to me what I am doing wrong?

Answer 1

The shape is the issue

a = np.arange(3).reshape(1,3)
b = np.arange(3,6).reshape(1,3)

np.dot(a, b)

Traceback (most recent call last):

  File "<ipython-input-88-c9cc415545b4>", line 1, in <module>
    np.dot(a, b)

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


c = b.reshape(3,1)

np.dot(a,c)
array([[14]])