outer product calculation error

[shuiyiwensi]

according to this and this the outer product of a b and outer product a.T b.T should not be the same

but when I do this
import numpy as np
a = np.array([[1], [2], [3]])
b = np.array([[4], [5], [6]])
col_result=np.outer(a, b)
row_result=np.outer(a.T, b.T)
print(col_result)
print(row_result)

the result are equal

[eric-wieser]

np.outer is weird by design. From the docs, "Input is flattened if not already 1-dimensional". Your 2D input is flattened to 1D first.

Are you after np.multiply.outer(a, b), which produces a four dimensional array similar but not identical to this answer in your link

[mattip]

@shuiyiwensi did you resolve the issue? I am closing, please reopen with a new example if you feel something is still unclear.