Matrix Vector multiplication

Asked Jul 18 '19 at 12:15

Active Jul 18 '19 at 12:56

Viewed 263 times

I have a rather simple question which surprisingly i could find the answer theres a matrix $U $ whith is $4*4$ and a vector $A$ which is $4*1$ and when I wand to multiply them by $U.A$ operator i get this :

Dot::rect: Nonrectangular tensor encountered.

so does anyone know how can i multiply them together?

U = {{1,2,1,1},{1,3,2,2},{0,2,0,1},{0,1,2,1}}

and

A = {{1},{1},{1},{1}}

edited Jul 18 '19 at 12:56

Thies Heidecke

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asked Jul 18 '19 at 12:15

Jason

2

Post your U and A please. – Kiro Jul 18 '19 at 12:20
@Kiro Consider any arbitrry matrices i tried different matrices. all of the mgive me the same error regardless – Jason Jul 18 '19 at 12:25
6

Did you wrap MatrixForm around any of them during definition? This is a common pitfall: https://mathematica.stackexchange.com/a/18395/43522 – Sjoerd Smit Jul 18 '19 at 12:30
@Sjoerd Smit Well actually I defined them using the toolbox basicmath assistant-> typesetting , which provide me an exat matrix form to fill – Jason Jul 18 '19 at 12:36
@Jason I can't reproduce your problem with arbitrary matrices. – Kiro Jul 18 '19 at 12:37
@Kiro I added the matrices – Jason Jul 18 '19 at 12:40
1

@Sjoerd Smit In fact thank you so much cz that was the problem – Jason Jul 18 '19 at 12:47
1

Concerning your unusual form of A, this discussion and its linked materials may be of interest for you. – Roman Jul 18 '19 at 13:51

Matrix Vector multiplication

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