Re: How to transpose vector?
- To: mathgroup at smc.vnet.net
- Subject: [mg14678] Re: [mg14669] How to transpose vector?
- From: "R NOTESTINE" <GVZRN at pmn1.maths.nott.ac.uk>
- Date: Sun, 8 Nov 1998 21:15:37 -0500
- Organization: Maths, The University of Nottingham
- Sender: owner-wri-mathgroup at wolfram.com
On Sat, 7 Nov 1998, at 02:10:26 -0500,
Nobuhiko Tamura wrote:
> I have a problem about manupirating vectors. I wanted to make 3x3
> matrixtwo by using 3x1 vector alpha and beta. and I tried by
>
> >>Transpose[alpha].beta
>
> but it dosen't work. ...
We must use actual matrices to distinguish row & column vectors:
The usual Mathematica method of using simple lists for vectors does
not distinguish between row and column vectors. Using this scheme, all
of these vectors are of the same type, and the Dot function returns
the sum of the products of corresponding elements.
If we wish t have row and colmn vectors, we are really talking about
matrices (or 2D tensors) in which there is either only one row or one
column.
So a row vector would be {{1,2,3}},
and its transpose is the column vector {{1},{2},{3}}.
In this case, the Dot function performs the normal matrix
multiplication, which is just what is desired!
Ronald D. Notestine
On Sabbatical for 1998/99 at:
Maths, Nottigham U., Nottingham NG7 2RD, UK tel: +44-(0)115-951-4938
email: gvzrn at pmn1.maths.nottingham.ac.uk
Permanent address (from late 1999, again) Ronald D. Notestine
Faculty of Management, Chukyo University 101-2 Yagoto-Honmachi,
Showa-ku, Nagoya 466-8666 tel: +81-(0)52-832-2151
email: ronald at mecl.chukyo-u.ac.jp