RE: Matrix Multiplication (with a twist)
- To: mathgroup at smc.vnet.net
- Subject: [mg69004] RE: [mg68951] Matrix Multiplication (with a twist)
- From: "David Park" <djmp at earthlink.net>
- Date: Sat, 26 Aug 2006 02:04:50 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Bruce,
Use NonCommutativeMultiply and Inner.
A = {{e, f}, {g, h}};
B = {{a, b}, {c, d}};
Inner[#1 ** #2 &, A, B]
{{e ** a + f ** c, e ** b + f ** d}, {g ** a + h ** c, g ** b + h ** d}}
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: Bruce Colletti [mailto:vze269bv at verizon.net]
To: mathgroup at smc.vnet.net
For matrix A = {{e,f},{g,h}} and B = {{a,b},{c,d}}, Mathematica returns
their product
A.B = {{ae+cf,be+df},{ag+ch,bg+dh}}
However, I want to treat multiplication of numeric variables as
noncommutative in order to instead obtain the result
{{ea+fc, eb+fd},{ga+hc,gb+hd}}
How would this be done in v5.2? Thanks.
Bruce