problem with solving a system of equations

#1 Posted: 8/17/2024 12:07:15 AM

Prmtv

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Hello!

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

00.sm (9 KiB) downloaded 34 time(s).

Thanks!

#2 Posted: 8/17/2024 5:49:32 AM

Martin Kraska

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

00_Kr.sm (13 KiB) downloaded 27 time(s).

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

Martin Kraska Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx

#3 Posted: 8/18/2024 12:20:41 AM

Prmtv

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Group: User

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

00_Kr.sm (13 KiB) downloaded 27 time(s).

how to choose the right one initial guess?

#4 Posted: 8/18/2024 4:15:52 AM

overlord

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Wrote
how to choose the right one initial guess?

What I can suggest is to use right solver.

#5 Posted: 8/18/2024 7:25:46 PM

Prmtv

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Group: 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 Posted: 8/18/2024 7:51:08 PM

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 Posted: 8/22/2024 11:23:22 PM

Prmtv

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Group: User

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 Posted: 8/23/2024 12:05:06 AM

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 Posted: 8/23/2024 3:42:01 AM

Prmtv

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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

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

The problem occurs when using the function "FindRoot"

#10 Posted: 8/23/2024 4:11:17 AM

overlord

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Group: Moderator

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 Posted: 8/26/2024 1:33:45 AM

Prmtv

0 likes in 49 posts.

Group: 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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problem with solving a system of equations - Messages