really silly nit: why 3+5j instead of 3+5i?

Grant Griffin g2 at seebelow.org
Sun May 14 14:51:10 EDT 2000


Jeff Petkau wrote:
> 
> Can anyone tell me why Python uses 'j' instead of 'i' for imaginary
> numbers? I know this is really minor, but every bloody time I
> use complex numbers I forget and type i's, and have to go back
> and change them all to j's. My fingers just won't learn.
> 
> [History of imaginary number notation, according to Google: Euler
> invented the things, and he used 'i'. Gauss made 'em famous, and
> he used 'i'. Everyone since then has used 'i' except for electrical
> engineers, and they probably just changed it to cause trouble. 

We design computers for exactly the same reason.  (What could possibly
be more aggravating than a thing that does exactly what you tell it? ;-)

Actually, we use 'j' because 'i' was already taken as the standard
symbol to represent electrical current.  OK, so why didn't we just use
'c' for current?  Well, I'm glad you asked.  It's because 'c' was
already taken as the standard symbol for capacitance.  (And don't even
get me started on the fact that 'r' was already in use for
resistance...)

Or at least that's the party line.  In truth, we use 'j' to represent
sqrt(-1) for exactly the same reason we use a convention for the
direction of current which is exactly the opposite of the direction the
electrons actually travel: because it drives physicists crazy.  (And if
we pick up a few mathmeticians or whatever along the way, well, that's
just gravy. ;-)

welcome-to-our-parlors-said-the-spiders-to-the-flys-<wink>-ly y'rs,

=g2
-- 
_____________________________________________________________________

Grant R. Griffin                                       g2 at dspguru.com
Publisher of dspGuru                           http://www.dspguru.com
Iowegian International Corporation	      http://www.iowegian.com



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