MATLAB Answers

give constant parameters to fitnlm

4 views (last 30 days)
FastCar
FastCar on 15 Dec 2018
Commented: Walter Roberson on 16 Dec 2018
I want to use fitnlm (rather than fminsearch and a cost function) because it has the built in statistics. I need to run the fit of the model with different costant parameters but I am not able to tell the function to pick a parameter from the workspace (the function return an error if I give three arguments like @(parameterToOptimise,xData,constantParameter).
My example is:
fit function and the values to fit are y and I have a constraint on the area under the curve that is A (depending on the fit problem).
I would like to write
@(α,x,Area)[(α+1)*Area/(-)*] (luckly and are constant, so I can write the numerical values), but I am not able to give a constant parameter to the function

  0 Comments

Sign in to comment.

Accepted Answer

Image Analyst
Image Analyst on 15 Dec 2018
fitnlm() makes a best fit of your model to your data. I don't believe it takes into account some criteria like the area under the fitted curve is in some range.
I'm attaching a demo to fit a power law with fitnlm(). Change the model to be what you need. If you need more help, attach your data in a .mat file.
0000 Screenshot.png

  3 Comments

FastCar
FastCar on 15 Dec 2018
Thank you, but I came across the str2func function that does exactly what I want (not imposing a constraint on the area, but passing extra parameters to the model function.
zaydon latif
zaydon latif on 15 Dec 2018
Image Analyst hello sir , i want help me , i want you email to speak the problem .
i will gratiful to you .
Walter Roberson
Walter Roberson on 16 Dec 2018
Image Analyst has a personal policy of not discussing user question in email . Ask your question publicly and someone might volunteer .

Sign in to comment.

More Answers (0)

Community Treasure Hunt

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

Start Hunting!