HP-35’s x^y Why?

[J-F Garnier]

(11-03-2021 05:46 PM)robve Wrote:  

(11-03-2021 03:43 PM)J-F Garnier Wrote:  Rob, I can be interested by comparing math algorithms, but not by systematic denigrating.

Math, logic and engineering people are not subject to critique or discussion here.

Justly criticizing a machine or a technology is not denigrating. There is no rationale to anthropomorphize objects or algorithms. There is no systematic aspect to that either. Really strange to hear accusations to intentionally repeatedly criticizing the same thing. I've never posted anything negative about the HP 35s before in my life.

Sorry if I over-reacted (not usual for me), and the term 'denigrate' was maybe not the right one. But there was no rationale to judge the HP implementation worse (worst than Sharp?). The reason of the 125^(1/3) HP result was easy to check and quite obvious.

(11-03-2021 05:46 PM)robve Wrote:  

(11-03-2021 03:43 PM)J-F Garnier Wrote:  It can also be fooled to get it wrong
(-128)^(1÷6.999) = 2.00019808 ???

For the record, this quote is from Albert, not me.

Basically, I don't agree with you that a 'correct' y^x implementation must check that the x value is close to the reciprocal of an integer, to manage the case of odd nth-root of negative numbers. I understand that Sharp and others do it and give nice results, but it seems very artificial for me, and prone to wrong assumptions as Albert pointed out. It seems to me that having a y^(1/x) function is much more robust.

J-F