Re: Usage of complex numbers?

From: Peter O. Brackett (no_such_address_at_ix.netcom.com)
Date: 03/11/04 

Date: Thu, 11 Mar 2004 22:34:46 GMT

Chris:

Hi Chris...

[snip]
> Stinkin quaternions? If you want to compose rotations in three dimensions
> quaternions are the way to do this fast. Or would you rather multiply
> rotation matrices?
>
> Bye,
> Chris Dams
[snip]

I thought Oliver Heaviside put the run to quarternions almost a century ago.

Today in electrical/communications Engineering we seldom rotate in 3D.

I suppose crystalographers and others do that kinda stuff. But 3 is not a
big enough dimensionality
for coding work... need way higher N D's to get any coding gain.

We EE's do need to rotate in much higher dimensions, all the way up to say
24D where
the Leech Lattice hangs... and it seems we need to use rotation matrices.
At least that's what I've
done in code searches. Of course for certain N's, besides the quaternions
for N=3, there are the octonions,
dodecatonions, etc... they are cute but they just don't fill the needs in
all those N-dimensional spaces where
interesting lattice codes hang...

:-) 

--
Peter
Professional Consultant - Signal Processing and Analog Electronics
Indialantic By-the-Sea, FL

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