Thread Subject: Non-linear regression help.

Hello all,
I want to do non-linear regression by fitting the model (let say, y = a1*x+b1*x^2+c1*x^3/exp(d1*x^4)) where the parameter (say "c1") must be in between (0 to 1), and others can be of any values. How can I perform my job?

Thanks in advance?

-- Akand

"Akand Islam" <awislam@crimson.ua.edu> wrote in message <ija457$ppe$1@fred.mathworks.com>...
> Hello all,
> I want to do non-linear regression by fitting the model (let say, y = a1*x+b1*x^2+c1*x^3/exp(d1*x^4)) where the parameter (say "c1") must be in between (0 to 1), and others can be of any values. How can I perform my job?
>
> Thanks in advance?
>
> -- Akand

Hi Akand,
Look at FEX, where the function LMFnlsq solves a similar problem.
Mira

"Miroslav Balda" wrote in message <ijakpp$bvp$1@fred.mathworks.com>...
> "Akand Islam" <awislam@crimson.ua.edu> wrote in message <ija457$ppe$1@fred.mathworks.com>...
> > Hello all,
> > I want to do non-linear regression by fitting the model (let say, y = a1*x+b1*x^2+c1*x^3/exp(d1*x^4)) where the parameter (say "c1") must be in between (0 to 1), and others can be of any values. How can I perform my job?
> >
> > Thanks in advance?
> >
> > -- Akand
>
> Hi Akand,
> Look at FEX, where the function LMFnlsq solves a similar problem.
> Mira


Dear Miroslav Balda,
Thanks for response. So far I understand, I have to make a function file , and then calling the "LMFnlsq" with initial guesses like other optimization tools. However where I will specify that certain parameter will be in certain limit? Can you please show me how I will call "LMFnlsq" with my specification.

Thanks again.

-- Akand