Re: Matrix multiplication problem fixed via dot operation.

*To*: mathgroup at smc.vnet.net*Subject*: [mg64600] Re: Matrix multiplication problem fixed via dot operation.*From*: Bill Rowe <readnewsciv at earthlink.net>*Date*: Thu, 23 Feb 2006 00:35:37 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

On 2/22/06 at 5:58 AM, c1572young at earthlink.net (Chris Young) wrote: >To answer my own posting, it looks like the "dot" operator is >needed when the matrices aren't both square. >E.g.: a row vector with components a and b times a column vector >with components c and d will yield the correct result, the >dot-product. >I'm still puzzled why Mathematica doesn't do the same thing without >the dot. Because it is very useful to do things like: In[3]:={a,b} {c,d} Out[3]={a c,b d} And since for me (and I suspect most others) the need to multiply lists of things in the manner above arises much more frequently than the need for matrix multiplication, I am glad Mathematica reserves the implied multiplication syntax for this rather than matrix multiplication when matrices are involved. -- To reply via email subtract one hundred and four