Curve Fitting Problem

[Sergei Steshenko]

Applications From Scratch: http://appsfromscratch.berlios.de/


--- On Thu, 6/26/08, A. Kalten <akalten at comcast.net> wrote:

> From: A. Kalten <akalten at comcast.net>
> Subject: Curve Fitting Problem
> To: help-octave at octave.org
> Date: Thursday, June 26, 2008, 3:57 PM
[snip]
> I suspect that the only solution would be to write a
> custom least squares program.
> 
> AK
> 
>

Maybe not.

If I understand your problem correctly, is more or less like this;

1) there is f(x) to be approximated;
2) the desired approximation is:

a * x^2 + b * x + c;

3) for example, 'a' above is for whatever reason predetermined.

Then, I think, you need to approximate

f(x) - a * x^2

with

b * x + c

, i.e. you can use the existing curve fitting function on a different 
input function.

Regards,
  Sergei.