MATLAB Answers

0

Nonlinear material model fit

Asked by Kálmán Németh on 22 Nov 2019 at 14:01
Latest activity Commented on by Image Analyst
on 23 Nov 2019 at 4:59
Hello there,
I have a few model functions, for example: y=2(x^2-1/x)(C1+C2/x).
I need to fit the parameters for a table of tension test data.Also, i would like to use different error functions, not just least root means square. How can i solve that?
Don't even know how to go about it.
Thanks

  0 Comments

Sign in to comment.

1 Answer

Answer by Image Analyst
on 22 Nov 2019 at 14:41
 Accepted Answer

fitnlm() is one of my favorite MATLAB functions. See my attached demos where I use fitnlm() to fit a variety of different functions. I think you'll be able to figure out how to make changes. If you can't, then attach some sample data and I'll modify the demo for you.

  2 Comments

Kálmán Németh on 22 Nov 2019 at 23:17
Thank you, however i have some questions.
Can i somehow prescribe for the parameters to be positive values or between some value? Also can i modify the error function used in this method?
Image Analyst
on 23 Nov 2019 at 4:59
If you can, I don't know how.

Sign in to comment.