problem with solving a system of equations

#1 Pubblicato: 17/08/2024 00:07:15

Prmtv

0 apprezzamenti in 49 post.

Gruppo: User

Hello!

Such a problem appeared. Please tell me what's the matter

00.sm (9,79 KiB) scaricato 1572 volta(e).

Thanks!

#2 Pubblicato: 17/08/2024 05:49:32

Martin Kraska

1.361 apprezzamenti in 2.275 post.

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roots() in this case needs a custom initial guess.

00_Kr.sm (13,52 KiB) scaricato 1647 volta(e).

2024-08-17 00_46_56-SMath Solver - [00.sm_].png

Technische Mechanik mit SMath Studio: https://link.springer.com/book/10.1007/978-3-658-50592-9

#3 Pubblicato: 18/08/2024 00:20:41

Prmtv

0 apprezzamenti in 49 post.

Gruppo: User

Wrote
roots() in this case needs a custom initial guess.

00_Kr.sm (13,52 KiB) scaricato 1647 volta(e).

how to choose the right one initial guess?

#4 Pubblicato: 18/08/2024 04:15:52

overlord

600 apprezzamenti in 1.381 post.

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Wrote
how to choose the right one initial guess?

What I can suggest is to use right solver.

#5 Pubblicato: 18/08/2024 19:25:46

Prmtv

0 apprezzamenti in 49 post.

Gruppo: User

Wrote

Wrote
how to choose the right one initial guess?

What I can suggest is to use right solver.

how is the order of output of variables determined? From function "Unknowns"?

#6 Pubblicato: 18/08/2024 19:51:08

overlord

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Wrote
how is the order of output of variables determined? From function "Unknowns"?[/attach]

My guess and and experience is they are ordered alphabetically.

#7 Pubblicato: 22/08/2024 23:23:22

Prmtv

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Wrote

Wrote
how to choose the right one initial guess?

What I can suggest is to use right solver.

Thanks!

But when creating exe-file required variables a, b, B, t = 1. Why does this happen? Or is this a feature of the plugin "Nonlinear solvers"?

#8 Pubblicato: 23/08/2024 00:05:06

overlord

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I can't know what you have done without your sheet.
However, this was not an issue when I saved it as an exe.

Regards

#9 Pubblicato: 23/08/2024 03:42:01

Prmtv

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Wrote
I can't know what you have done without your sheet.
However, this was not an issue when I saved it as an exe.

Regards

If I use the function "al_nleqsolve" then everything really works

The problem occurs when using the function "FindRoot"

#10 Pubblicato: 23/08/2024 04:11:17

overlord

600 apprezzamenti in 1.381 post.

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It is due to some bug or miscode for FindRoot().
Or this is totally SMath result parse method.
Your solution (A) is stored symbolic.
Make it totally numeric by eval().
Exe file can show correct results after that.

Regards

#11 Pubblicato: 26/08/2024 01:33:45

Prmtv

0 apprezzamenti in 49 post.

Gruppo: User

Wrote
It is due to some bug or miscode for FindRoot().
Or this is totally SMath result parse method.
Your solution (A) is stored symbolic.
Make it totally numeric by eval().
Exe file can show correct results after that.

Regards

Thanks!

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