Hello Han,
As per my understanding you are trying to fit the data into a custom equation of the required form but are getting imaginary coefficients for the parameters.
It might be because of an error in importing data. Try to make sure you have imported the right data as x data and y data in the “Select data” option in the “Data” tab in curve fitter.
The given data was:
x: 836 1264 2236 3768
y: 0.836 1.264 2.236 3.768
These points lie on a straight line but that does not seem the case in the screenshot you have shared. Hence there might be an issue with the data importing.
On importing the data correctly, the result looks as follows:
Please refer to the following documentation to know more about curve fitting app.
- https://www.mathworks.com/help/curvefit/curvefitter-app.html?searchHighlight=curve%20fitting%20app&s_tid=srchtitle_support_results_1_curve%2520fitting%2520app
- https://www.mathworks.com/support/search.html/videos/how-to-perform-curve-fitting-using-the-curve-fitting-app-in-matlab-1613394490506.html?fq%5B%5D=asset_type_name:video&fq%5B%5D=category:curvefit/index&page=1
I hope this resolves the issue you were facing.