SMath Logo

SMath

SMath vs Mathcad

Login Registrati

SMath vs Mathcad - Messaggi

#1 Pubblicato: 06/08/2024 11:32:14
Valery Ochkov

Valery Ochkov

67 apprezzamenti in 713 post.

Gruppo: User

I can solve this problem in Mathcad - see pls the picture.
But cannot in SMath - see the SMath-file :-(
Help please
Stud-Mathcad.png
6-1-Mister-Class-a-b-c.sm (15,82 KiB) scaricato 1616 volta(e).
#2 Pubblicato: 06/08/2024 13:22:51
Alvaro

Alvaro

1.139 apprezzamenti in 1.805 post.

Gruppo: User

Hi. Try this function, from Viacheslav ALGLIB plugin.

nleq.png

Best regards.
Alvaro.
1 utenti hanno apprezzato questo post
Valery Ochkov 06/08/2024 14:30:00
#3 Pubblicato: 06/08/2024 14:34:07
Valery Ochkov

Valery Ochkov

67 apprezzamenti in 713 post.

Gruppo: User

Thanks and sorry!
I do not see in your solution derivatives!
???

#4 Pubblicato: 06/08/2024 18:36:47
Martin Kraska

Martin Kraska

1.361 apprezzamenti in 2.275 post.

Gruppo: Moderator

Here is a version with Maxima Fit(). Note that Fit() uses a least squares procedure, whereas Mathcad obviously directly minimizes the average linear distance between data points and model.
Ordinary linear regression with slope and intersect is a least squares fit for the vertical distance.

6-1-Mister-Class-a-b-c_kr.sm (35,92 KiB) scaricato 1593 volta(e).
2024-08-06 13_32_52-SMath Solver - [6-1-Mister-Class-a-b-c_kr.sm_].png
Technische Mechanik mit SMath Studio: https://link.springer.com/book/10.1007/978-3-658-50592-9
1 utenti hanno apprezzato questo post
Valery Ochkov 06/08/2024 18:53:00
#5 Pubblicato: 06/08/2024 19:22:00
Valery Ochkov

Valery Ochkov

67 apprezzamenti in 713 post.

Gruppo: User

Is there in SMath or Maxima the median-median regression
6-2-Mister-Class-MM.png

#7 Pubblicato: 07/08/2024 00:29:39
Martin Kraska

Martin Kraska

1.361 apprezzamenti in 2.275 post.

Gruppo: Moderator

Interesting paper. Yet the authors keep one question out of scope: In case of orthogonal distance minimizing (be it linear or quadratic), rescaling of the data matter. (other than with ordinary linear regression). This means that you get different results if you provide your data not in cm but in mm.
Perhaps the data should be scaled such that the uncertainty (measurement error) is of similar numeric value for x and y.
Technische Mechanik mit SMath Studio: https://link.springer.com/book/10.1007/978-3-658-50592-9
#8 Pubblicato: 07/08/2024 02:01:47
Valery Ochkov

Valery Ochkov

67 apprezzamenti in 713 post.

Gruppo: User

See please three plots
6-2-Mister-Class-Dir.png

#9 Pubblicato: 07/08/2024 02:12:28
Valery Ochkov

Valery Ochkov

67 apprezzamenti in 713 post.

Gruppo: User

See please more
6-6-CKO.png
#10 Pubblicato: 07/08/2024 15:24:46
Martin Kraska

Martin Kraska

1.361 apprezzamenti in 2.275 post.

Gruppo: Moderator

Wrote

See please three plots
6-2-Mister-Class-Dir.png



The perpendicular distance is only geometrically perpendicular in the graph if the axes tick ratio is 1 (as I tried to set in my earlier post) unless you introduce an anisotropic metric for the distance (or standardize the quantities).
Technische Mechanik mit SMath Studio: https://link.springer.com/book/10.1007/978-3-658-50592-9
#11 Pubblicato: 07/08/2024 19:51:31
Alvaro

Alvaro

1.139 apprezzamenti in 1.805 post.

Gruppo: User

Hi. Chosen different guess values, we can reproduce the maxima result. Also, notice that meanwhile the Maxima MSE function decreases, the "classical" one increases. I'm not sure how to call Maxima MSE for implicit functions.

mse.sm (25,22 KiB) scaricato 1636 volta(e).

Best regards
Alvaro
  • Nuovi post
  • Nessun nuovo post