Complex conjugate function for the 42s?

[Hal Bitton in Boise]

Hi all.

Just realized that my 42s doesn't seem to have a conjugate function.
There seems to be no mention of it the users guide either. Granted, it's easy enough to decompose the complex number, CHS, and recompose, but in so doing the contents of the T register is lost.
Also granted, a simple subroutine would resolve this issue.

If indeed "conjugate" is excluded from the 42s, any thoughts as to why?
Best regards, Hal

[Karl Schneider]

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Just realized that my 42s doesn't seem to have a conjugate function.

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Just now?

;-)

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There seems to be no mention of it the users guide either. Granted, it's easy enough to decompose the complex number, CHS, and recompose, but in so doing the contents of the T register is lost.

...

If indeed "conjugate" is excluded from the 42s, any thoughts as to why?

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The HP-42S has no menu of intrinsic complex-number functions or direct entry of complex numbers, as the RPL-based models have -- including the HP-28C and HP-28S that debuted earlier. Therefore, the Re(), Im(), and Arg() functions are missing from the HP-42S as well.

Loss of stack t-register for these operations is another good point.

I believe that a complete ('sticky') menu, even at the cost of separating "COMPLEX" into two three-keystroke functions "R->C" and "C->R", would have been a very good idea.

Here's a set of complex-number functions for the HP-15C:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cgi?read=137175#137175

-- KS

Edited: 26 Oct 2008, 11:13 p.m.

[Hal Bitton in Boise]

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Just now?

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Well, I've only had my 42S for a few months, and have not run a lot of complex numbers through it. 8^\

I would say that the rational behind the omition of these functions on the 42s (Re, Im, Arg, Conj) is the ease of complex number decomposition (and re-composition). There still is of course the T reg issue, but just entering complex numbers obliterates the T register anyway, so there you go...3 (complex) registers are enough I suppose.

Thanks and best regards, Hal