Hp50g MES

[Tugdual]

Does anybody know what algorithm is used in the Hp50g Multiple Equation Solver?

[Joe Horn]

The HP Solve Equation Library Application Card Owner's Manual says on page 169:

"When you solve problems using the Multiple-Equation Solver, the application uses the same numeric root finder that's used by the HP Solve application, which is built into the HP 48."

I assume that the same is true for the HP 50g.

[Tugdual]

(07-10-2020 03:27 AM)Joe Horn Wrote:  The HP Solve Equation Library Application Card Owner's Manual says on page 169:

"When you solve problems using the Multiple-Equation Solver, the application uses the same numeric root finder that's used by the HP Solve application, which is built into the HP 48."

I assume that the same is true for the HP 50g.

Thanks Joe. Would that then be a non linear equation solver? Like Levenberg-Marquardt method?

[Joe Horn]

(07-10-2020 10:44 AM)Tugdual Wrote:  Would that then be a non linear equation solver? Like Levenberg-Marquardt method?

Anybody know? If it's the same as the solver that HP first introduced in the HP-34C, then it's a "modified secant iteration method" as explained here by Dr Kahan himself in 1979: https://people.eecs.berkeley.edu/~wkahan...LVEkey.pdf

[JurgenRo]

(07-10-2020 12:13 PM)Joe Horn Wrote:  

(07-10-2020 10:44 AM)Tugdual Wrote:  Would that then be a non linear equation solver? Like Levenberg-Marquardt method?

Anybody know? If it's the same as the solver that HP first introduced in the HP-34C, then it's a "modified secant iteration method" as explained here by Dr Kahan himself in 1979: https://people.eecs.berkeley.edu/~wkahan...LVEkey.pdf

Thanks for the reading, Joe!

[ndzied1]

Not sure if this is what is used in the 50g but here is an HP patent for a multiple equation solver. It seems to be more about the multiple equation part than the solving of each equation.
https://patents.google.com/patent/US5175700
Method and apparatus for solving multiple equations

It also references this patent:
https://patents.google.com/patent/US4845652A/en
Generic equation solver interface for solving mathematical equations

Very much wish the Prime will eventually incorporate this type of multiple equation solving.

[Thomas Okken]

It sounds like this older topic might be relevant... not my area of expertise but hoping it may be useful: Multiple equation solver for the HP-28C (program)

[Tugdual]

Thanks all for the replies.
So to summarize it would be a sort of combination of an algo to try to solve obvious solutions, when only one variable remains and/or a secant method applied to multiple variables, hence something resembling https://en.wikipedia.org/wiki/Broyden%27s_method to expand on mutliple variables.