How to get the fitted data by using Matlab's "Fit" Function?

31 次查看（过去 30 天）
Zheng
Zheng 2012-9-21
For example, by using below code
load franke;
fitresult = fit( [x, y], z, 'poly33' );
From fitresult, I can get the formula used to fit x,y and z data
But how can I get the fitted data matrix via this "fit" function?

请先登录，再回答此问题。

采纳的回答

Wayne King
Wayne King 2012-9-22
It gives you a 1-D vector, but that 1-D vector is a polynomial in two variables, hence it is a function of the form f(x,y)=z
Calling
formula(fitresult)
shows you exactly what the terms in x and y the coefficients multiply

更多回答（1 个）

Wayne King
Wayne King 2012-9-22
Hi, you can use the coeffvalues() method on the fitresult object.
coeffs = coeffvalues(fitresult);
That will give you the coefficients of your polynomial in x and y.
To see how those coefficients enter into the polynomial equation:
formula(fitresult)
  2 个评论
Zheng
Zheng 2012-9-22
Thanks, Wayne. But how can I use this formula to calculate the surface (shown as below)? This formula can only help me get a 1-D vector, not 2-D matrix.
grace
grace 2013-2-22
May I know what is the code for goodness of fit? coeffs = coeffvalues(fitresult); Similarly, rsquare = code(fitresult); I wanted to get the rsquare values from cftool to display in command window.

请先登录，再进行评论。

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

Community Treasure Hunt

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

Start Hunting!

Translated by