How to extract the parameters through curve fitting

Hi all,

I've an experiment data which collect from thin-film transistor.

Here, I would like to obtain the paramters (mark with red square) throuhg curve fitting.

I've tryed the cftool to do that, unfortunately, it's fail....becasue I'm new with the curve fitting with matlab.

Can anyone teach me how to start conduct it?

where,

W/L=0.25

VTH=3.11

VD=0.1

Answer 1

[Sulaymon Eshkabilov]

(1) Import the data using readtable(), e.g:

D = readtable('IdVg.xlsx');
v=table2array(D(:,1));
TR=table2array(D(:,2));

(2) Use custom equation in cftool and insert your formulation in terms x variable.

[Chuanjung Lin]

Hi Sulaymon,

Thank you for your feedback, I've tyed this method. And detail as following,

(1) Setting "Exclude by Rule" to prevent negative value resulting in fitting error

(2) Type the formula in to box, and click "Fit Options" set the Lower and Uper.

(0.25) * (a/(1+b))*(((x-2.5)/c)^(b))*(1.77e-8)*(x-2.5)*0.1

And the result as the attahcment

[Steven Lord]

Export the fit to the workspace.

Use the coeffvalues function on the fit in the workspace to extract the coefficients. There are also a number of other functions you can call to obtain information about the fit.