Thread Subject: how to curvefit a part of curve

I just want to curve fit a part of curve. But I want to include entire curve when i analyze it. The curve fitting should consider the points only of that part while fitting. It should not consider all other points while it fits. Can anyone help me out in this regard....

I hope you guys understood my question.

"Sandeep gande" <coolsandeepg@yahoo.com> wrote in message <hbj6fo$pc6$1@fred.mathworks.com>...
> I just want to curve fit a part of curve. But I want to include entire curve when i analyze it. The curve fitting should consider the points only of that part while fitting. It should not consider all other points while it fits. Can anyone help me out in this regard....
>
> I hope you guys understood my question.

Yes, I understand your question.

The model that you might choose will drive what
you do, and how you will analyze this.

The simplest way to solve your problem is to use a
weighted regression. Assign the irrelevant points a
weight of zero.

John

"Sandeep gande" <coolsandeepg@yahoo.com> wrote in message <hbj6fo$pc6$1@fred.mathworks.com>...
> I just want to curve fit a part of curve. But I want to include entire curve when i analyze it. The curve fitting should consider the points only of that part while fitting. It should not consider all other points while it fits. Can anyone help me out in this regard....
>
> I hope you guys understood my question.

From what I understand, the curve fitting toolbox has facilities for doing exactly what you are asking for already built in

Regards

Dave robinson

Yes, using the Ezyfit toolbox :
http://www.mathworks.com/matlabcentral/fileexchange/10176
you just need to select the part of the data you want to fit using the "Data Brushing tool" (available since Matlab 7.6), and then you use the function "showfit" with the option "extrapol / data" (see http://www.mathworks.com/matlabcentral/fx_files/10176/3/content/ezyfit/html/ezyfit_settings.html for the settings).
Hope this helps,
Fred

"Sandeep gande" <coolsandeepg@yahoo.com> wrote in message <hbj6fo$pc6$1@fred.mathworks.com>...
> I just want to curve fit a part of curve. But I want to include entire curve when i analyze it. The curve fitting should consider the points only of that part while fitting. It should not consider all other points while it fits. Can anyone help me out in this regard....
>
> I hope you guys understood my question.