Fitting experimental data to find a function

I have an experimental data I=f(t) and I want to find the equation of This trend.

Answer 1

[Gareth Lee]

You can try polyfit function or other curve fit function, i.e. nlinfit or lsqcurvefit,to find proper equation. you also use cftool to curve or regress your data.

[Anoire BEN JDIDIA]

I'm currently testing curve fitting toolbox but how can I know which is the best regression. Ps: in my case is a non linear regression

[Gareth Lee]

This is a complicate problem, it is hard to say which method is good. you only try it, and judge it with some mathematical index. I suggest that plot it firstly, and estimate the equation according to curve. try it, and obtain some good parameters.

Answer 2

[KSSV]

doc polyfit