non linear r squared through VBA

[prinzip]

Hello.

I would like to know if there a way or a build in function to calculate the non linear r squared value through VBA.

For the linear r squared value you just have to square the Correl build in function, but what about the non linear?

To make things clear, I uploaded a photo where for the given data series the linear r squared value is equal to 0.994118 and the r squared value for the given third grade polynomial is equal to 1 (which means that the polynomial fits your series 100%).

 

[sergioMabres]

Hi prin, I know of a way to do that, and involves only formulas (matrix and linear regression)
I got the sheet from Handbook of Biological Statistics: Polynomial regression a very good post about Polynomial regression
This guy he really knows what he is doing
The sample sheet is at http://udel.edu/~mcdonald/statpolyreg.xls
I hope is what you need
Cheers
Sergio