HP calcs are really not that accurate..

[Massimo Gnerucci]

(12-01-2017 07:49 PM)DA74254 Wrote:  I just sat here, reading the reverb memory thread and my thoughts started to spin about the sqrt(2).

To put it straight; HP sucks at math!
At least in RPN or in "inexact" mode

I put 2 on the stack and sqrt it 5 times, then squared it back. All my 5 HP's returned 1.99999999979 instead of 2.0. That goes for the Android Pro version as well.

On my Android phone and tab, I have the free42 (of course), realcalc+, RPNcalc, Prime and the default calc.

*All*, except the HP returns 2 after the 5-step sqrt/squared.

HW 49G+, 50G (in exact mode) and Prime in CAS returned correct results, though.
Maxima math on my PC returned correct result.

I'm not angry with HP, just very, very disappointed..

Start here (pp. 16-17)

Quote: unavoidable error caused by using finite computers to approximate nonfinite processes