Re: matrix times a vector

*To*: mathgroup at smc.vnet.net*Subject*: [mg49045] Re: matrix times a vector*From*: "Brien Alkire" <brien at rand.org>*Date*: Tue, 29 Jun 2004 04:50:30 -0400 (EDT)*Organization*: RAND Corporation*References*: <cbokn1$4bl$1@smc.vnet.net>*Reply-to*: "Brien Alkire" <bigtime at majorspam.com>*Sender*: owner-wri-mathgroup at wolfram.com

Simply transpose the matrix before mulitplying by {x,y}: Transpose[{{a,b}, {c,d}}] This extends without change to general nxn matrices. "David Salomon" <david.salomon at csun.edu> wrote in message news:cbokn1$4bl$1 at smc.vnet.net... > Question: > > The input {{a,b}, {c,d}}.{x,y} generates the output {a x+b y,c > x+d y}. > > How can I get the output x{a,b}+y{c,d} ? > > This is a special case of lists with two elements. How > can I extend this computation in an elegant way to lists > with N elements? > > with thanks, > > > |David Salomon | | > |Computer Science Dept. dsalomon at csun.edu | > |California State University http://www.ecs.csun.edu/~dxs | > |Northridge, CA 91330-8281 (818) 677-4954 | > |USA fax (818) 677-7208 | > | | > | Macintosh --- because you can see right through windows. | >