From: "Christopher R. Carlen"
Subject: Re: Audio noise in diff amps
Date: Thu, 19 Dec 2002 17:04:53 -0800
Organization: Sandia National Laboratories, Albuquerque, NM USA
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NNTP-Posting-Date: Fri, 20 Dec 2002 00:03:45 +0000 (UTC)
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John S. Dyson wrote:
> I'll look it up (again.) It has to do with whether it is sqrt(-1) or -sqrt(-1)
> or somesuch. Often, it ends up that EEs will use the i definition for j,
> but there really was a difference (or vice-versa). I found this odd fact in either an old
> IEEE journal or in a ref book. I'll try to revisit my 'steps' to remember where
> it is.
I have only ever found the usage of j as j=i=sqrt(-1). This would
really wreak havoc on communication effectiveness between engineers,
physicists, and mathematicians, if anyone was using j=-sqrt(-1).
Now what really does bug me, is that the mathematicians swap phi and
theta in the cylindrical and spherical coordinate systems from the wa
engineers use them. I am not sure how physicists do it anymore. I'll
have to check a physics book.
Also, ijk, vs. xyz basis vectors are a pain, but at least it's easier to
figure out what's going on than with swapped symbols.
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA