Precision problem with matrix inversion

[Maro]

(07-15-2015 08:28 PM)Anders Wrote:  ...
2) Solving linear equation system through a vector / matrix division is maybe the most basic linear algebraic function that an engineer or a student performs, so it needs to work also in RPN mode
....

This is basically the point. And it needs to work properly in algebraic and textbook mode too, which is NOT the case at the moment. It only works fine when using "approx([V]/[P])" but not for simply doing "[V]/[P]", which would be the most obvious way when working in Home environment ... Why that??

(07-15-2015 08:28 PM)Anders Wrote:  ...
3) HP matrix capable RPN calculators have been able to perform vector - matrix division correctly with sufficiently high precision for ~30 years until now with Prime (I know of HP 28C, HP 28S, 48SX, 50G), so of course it is possible to implement this correctly. These calculators had 2KBs+ of RAM (HP 28C had 2KB) and Prime have 3-4 magnitudes more RAM with 32MB. The "memory constraint" argument do not hold.
...

This is another point. The "old fashioned" 50g can do it without any problem in numerical mode (exact mode is not needed!). So what is the reason why the "powerful" Prime shouldn't be able to do this matrix inversion in a correct way in numerical mode too?? Perhaps somebody involved in the Prime development can further explain why the 50g succeeds and the Prime fails? What is the difference?

(07-15-2015 08:28 PM)Anders Wrote:  ...
5) Suggesting to use CAS mode, which is likely disabled in Exam mode, is not helpful for students if you want them to use RPN (or are you saying we should stop using RPN?)
...

+1