newRPL - Wiki examples for PEEK, POKE and NEWOB commands

[Marco Polo]

(09-27-2021 01:37 PM)Claudio L. Wrote:  

(09-25-2021 05:45 PM)JoJo1973 Wrote:  I'm collecting examples beginning from this old post

https://www.hpmuseum.org/forum/thread-97...#pid101856

but when I began experimenting I've found some difficulties: for example I can't get to solve this linear system:

a + x - 3 y + z = 2
-5 a + 3 x - 4 y + z = 0
a + 2 y - z = 1
a + 2 x = 12
(courtesy of Wolfram Alpha)

The solution is a=22/17 x=91/17 y=84/17 z=173/17 but MSOLVE can't converge: I've used {0 0 0 0} {12 12 12 12} as searching range and I got {0 0 0 0} and {-2 0 -1 -12} as residuals

If I constrain the four variables to be >0 I get {2.9999... 5.9646... 6.2512... 15.2711...} (I don't include the residuals.

I've also tried inverting the order of the searching range or adding >0 constraints, but to no avail.

A system of three equations fails to converge too, but a 2 equation system seems to work.

Interesting, I'm investigating why it does not converge.

Just tested with Solvesys on HP50g (real and Emu48): it converges very quickly