HP-71B Enhanced Math LEX

[J-F Garnier]

(03-17-2021 09:00 PM)Albert Chan Wrote:  

(04-27-2020 09:42 AM)J-F Garnier Wrote:  A little challenge for you : during my tests I found a minor problem in some of the new keywords of the previous test version (2b1, see post above). I didn't fix it yet (so still in 2b2, will fix it in a later version) and your mission, would you accept it, is to find the problem...
It's not a major problem, it will not crash your HP71 nor make your big engineering calculations completely fail, but still this is not fully correct and so it may be called a bug.
Hint: the HP75 and Series 80 don't have (and *can't* have) the same problem with these keywords...

It is almost a full year. Time flies ...
What was the bug ?
Is it fixed now ?

I almost forgot it... No, actually it is noted in my todo list but forgot to fix it in the final 2B version.
The problem is: finding the min element of an array made of Inf values incorrectly returns 9.999..E499 instead of Inf:
>DIM A(3)
>MAT A=(INF)
>AMIN(A)
9.99999999999E499
Same with MINAB and similar problem with -Inf and AMAX/MINAB. Not a big deal.

I recently identified a more serious bug, that was present since version 2A too:
raising a complex value to the real power -2 produces an incorrect result.
Z^(-2,0) was ok but Z^(-2) was wrong (computed as Z^2 instead).
This was caused by the changes I did to manage the z^2 operation as z*z in the version 2A.
It is fixed now in revision 2B7 (MATH2B7).

Thanks for your interest, Albert!

J-F