Why Inner doesn't work with Dot/List?

Asked Jul 11 '16 at 21:13

Active Jul 11 '16 at 21:13

Viewed 33 times

The recent question about generalizing Dot for list of matrices had a nice solution/comment using Inner.

Briefly, we have 6 matrices:

{a, b, c, x, y, z} = RandomReal[{0, 1}, {2, 2}] & /@ Range[6]

And we want to get three matrices {a.x, b.y, c.z}, then possible (per comment to original question) solution would be

Inner[Dot, {a, b, c}, {x, y, z}, List]

But it fails, complaining:

Length 2 of dimension 3 in

Why?

edited Apr 13 '17 at 12:55

Community

asked Jul 11 '16 at 21:13

BlacKow

@Kuba, you are right... At first I wanted matrices to depend on n, but then forgot it. – BlacKow Jul 11 '16 at 21:18
1

It is too late for me to focus properly but I think that is the reason: (9219) – Kuba Jul 11 '16 at 21:27
@Kuba Yeah... that explains it... Inner[Dot, Unevaluated@{a, b, c}, Unevaluated@{x, y, z}, List] works fine. Thanks! Care to post it as an answer? – BlacKow Jul 11 '16 at 21:33
Voted to mark it as a duplicate since there is nothing more to add. – Kuba Jul 11 '16 at 21:38

0 Answers0