Public apology to Valentin Albillo - Printable Version +- HP Forums ( https://archived.hpcalc.org/museumforum)+-- Forum: HP Museum Forums ( https://archived.hpcalc.org/museumforum/forum-1.html)+--- Forum: Old HP Forum Archives ( https://archived.hpcalc.org/museumforum/forum-2.html)+--- Thread: Public apology to Valentin Albillo ( /thread-204829.html) |

Public apology to Valentin Albillo - fhub - 11-13-2011
Hi Valentin!
First to our differences about the Laguerre method:
What changed my mind? Well, today I've slightly modified my WP34s Laguerre program, and suddenly I got an error message which I couldn't explain. Analyzing this problem I found that there was a misunderstanding between me and the WP34s about the absolute value of a complex number: I assumed that [cpx]ABS would of course return just a single real value, but the WP34s implementation returns a complex value with the ABS-value in X and 0 in Y!
Now about the 'style' of our communication:
I hope you accept my apology, Re: Public apology to Valentin Albillo - Marcus von Cube, Germany - 11-13-2011
I'm of course not Valentin, but as a person who has followed this dispute with some personal involvement (WP 34S is our baby, isn't it?) I very much appreciate your statement. I hope, Valentin will see it similarly. Marcus
"I's not the errors we make, it's how we deal with them."
Re: Public apology to Valentin Albillo - Alexander Oestert - 11-13-2011
:-)
Re: Public apology to Valentin Albillo - Paul Dale - 11-13-2011
I was sure I'd implemented a HYPOT command that calculated sqrt(x^2 + y^2). Must have been removed somewhere along the line :-(
Re: Public apology to Valentin Albillo - Marcus von Cube, Germany - 11-13-2011
Most probably superseded by cABS and R->P. But the function may be replaced by: cABS (or R->P) x<>y DROP.
Re: Public apology to Valentin Albillo - Paul Dale - 11-13-2011
"cABS +" is one step shorter :-) Alas, DROPY went away a long time ago.
Re: HYPOT and complex ABS - Dieter - 11-13-2011
Well, I remember some person suggesting a HYPOT command and another person saying this was not required since CPX ABS would do the same. ;-)
In fact, the complex ABS command evaluates sqrt(x^2 + y^2) exactly - it's done with 39 digits while only 32 are required. There is just one thing that looks a bit strange for me: consider a function that uses a complex argument while it always returns a real result. Do you think the result should still be returned as a complex number with a zero imaginary part? In other words: is it a good idea if the complex ABS function finishes with the C indicator set and a result in X Dieter
Re: Public apology to Valentin Albillo - Walter B - 11-13-2011
Quote: All complex functions of the WP 34S deal with pairs of registers in input and output. So does ^{C}ABS. Simply consistent :-)
Re: Public apology to Valentin Albillo - Dieter - 11-13-2011
Please see my other post in reply to Pauli's.
Dieter
Re: Public apology to Valentin Albillo - Walter B - 11-13-2011
Well, the basic assumption is anybody calculating complex functions wants to continue this way - so we better return a complex result. If, OTOH, some complex functions would return just a single number in a single stack level, a continuation in complex realm would become quite difficult.
Re: Public apology to Valentin Albillo - Ángel Martin - 11-14-2011
Excellent logic - I used the same convention in the 41Z with functions like ZABS, ZARG, etc. returning zero as imaginary part.
WP 34S complex mode - Marcus von Cube, Germany - 11-14-2011
Which leads me to the conclusion that CPX should be renamed i. We have dynamic register allocation so it's time for a complex stack and a complex mode going with it. We will save a lot of flash space in the keyboard, display and catalog handlers which we can spend better on a proper complex mode. No need to recode the subroutine behind label E to use cLN instead of LN. Let's do it the same way as the 15C!
Re: WP 34S complex mode - Paul Dale - 11-14-2011
Quote: - keyboard: yes.
- display: where?
- catalog handlers: no?
Doing a 15C style complex stack will be very invasive. Better will be real types (including complex) for the 43S.
Re: HYPOT and complex ABS - Bart (UK) - 11-14-2011
Quote:I disagree, I'd rather stay in complex mode because if I was to use the result as an argument for another function, it would likely be complex too (and thus save me putting 0 in Y). Re: Public apology to Valentin Albillo - Valentin Albillo - 11-14-2011
Quote: Of course, why not, thanks and let bygones be bygones.
Best regards from V.
Re: Public apology to Valentin Albillo - Walter B - 11-14-2011
Muchas grazias :-)
Re: WP 34S complex mode - Walter B - 11-14-2011
Quote:I fullheartedly concur :-) Surprise? |