Weighting of non-linear fit

3 次查看（过去 30 天）
Bryan
Bryan 2015-11-10
Hi,
I have made a rational fit function of some data using the cftool GUI. It works quite well.
I have some data points (X,Y) with standard error Ye (Y +/- Ye).
At first I made the rational fit model simply using the X,Y data points. But then I decided that I wanted to include the Y uncertainty of the data points in to model somehow. So I used weighting (w) to represent this, whereby:
w(i) = 1 / (Ye(i)^2))
w is a 1 by length(y) matrix
It worked!
However, I am a bit puzzeled. When I plot the model with observation bounds, I get larger observation bounds when I plot the unweighted model than when I plot the weighted model.
I thought that since the weighted model included data point uncertainty, that the observation bounds should be larger?
Have I done something wrong or am I just not yet understanding something that perhaps at first seems unintuitive?
Thanks Bryan

请先登录，再回答此问题。

回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Get Started with Curve Fitting Toolbox 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by