Three exponential fit with curve fitting toolbox

조회 수: 24 (최근 30일)
Katéri Tremblay
Katéri Tremblay 2020년 11월 4일
댓글: Asad (Mehrzad) Khoddam 2020년 11월 4일
Hi,
I'm using the Curve Fitting Toolbox in MatLab and I don't see a way to do a three term exponential fit. Is there a way I can do it? If the custom equation can be helpful, how can I use it for that kind of problem? And why MatLab Curve Fitting Toolbox doesn't offer the three term exponential fit?
Best regards,
Kateri.

답변 (2개)

John D'Errico
John D'Errico 2020년 11월 4일
You an always define your own custom model using fittype. Nothing stops you. But multiple term sums of exponential fits are often difficult to estimate well. Personally, if I was writing the curvefitting toolbox, I would leave it out too, just because most people lack good enough data or good enough starting values. So I would force the person who really wants to do that, to also know enough about what they are doing to have even a remote chance of success.
But nothing stops you from doing as you wish. As I said though, good data and good starting vaues will be crucial. If you allow it to choose its own random starting values, then expect possibly total crap for a result.

Asad (Mehrzad) Khoddam
Asad (Mehrzad) Khoddam 2020년 11월 4일
In the toolbox, there is an option to define a custom model.
  댓글 수: 2
Katéri Tremblay
Katéri Tremblay 2020년 11월 4일
Thanks for the reply! I tried to make an three term exponential fit by customizing an equation, but it doesn't work either. I obtain this:
Asad (Mehrzad) Khoddam
Asad (Mehrzad) Khoddam 2020년 11월 4일
If you have any ideas about the cofficients, you can set a lower and upper values for them instead of -Inf and Inf

댓글을 달려면 로그인하십시오.

카테고리

Help CenterFile Exchange에서 Interpolation에 대해 자세히 알아보기

제품


릴리스

R2020b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by