Given m x n matrix A and n x r matrix B how to write the following formula in np.einsum notation?
f(i) = \sum_{j,k} a_ij * b_jk
What will change in np.einsum if r x p matrix C will be added?
f(i) = \sum_{j,k,l} a_ij * b_jk * c_kl
Asked
Active
Viewed 156 times
0
Sengiley
- 221
- 2
- 7
-
1'sum_{j,k} a_ij * b_jk' should use 'ij,jk->i' – hpaulj Aug 19 '21 at 01:17
-
thanks! and for 3 matrices it seems to look like np.einsum("ij,jk,kl->i", a, b, c) – Sengiley Aug 19 '21 at 02:06
1 Answers
1
@Sengiley Despite you already answered yourself's question. A more general version that allows broadcasting is:
np.einsum('...ij,jk,kl->...i', a, b, c)
Shuhao Cao
- 221
- 1
- 7