RE: matrix times a vector
- To: mathgroup at smc.vnet.net
- Subject: [mg49030] RE: [mg49002] matrix times a vector
- From: "David Park" <djmp at earthlink.net>
- Date: Tue, 29 Jun 2004 04:50:05 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
David,
Is this what you want?
vector = {x, y};
matrix = {{a, b}, {c, d}};
vector.matrix
{a x + c y, b x + d y}
Or maybe...
vector .HoldForm /@ matrix
% // ReleaseHold
x {a, b} + y {c, d}
{a x + c y, b x + d y}
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: David Salomon [mailto:david.salomon at csun.edu]
To: mathgroup 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 |
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