How i can find the formula from an linear interpolation in cftool.

Hello,

I have 3 set of data. I use cftool, to make an interpolation of theses, and I want to know the formula of the surface.

I use interpolant linear method.

And I have a nice surface on answer and this :

Linear interpolant : f(x,y) = piecewise lenar surface computed from p where x is normalized by mean 551.1 and std 72.04 and where y is normalized by mean 1.499 and std 0.9631

Coefficients : p = coefficient structure

Goodness of fit: SEE : 4.093e+09 R-square : 0.9979 Adjusted R-square : Nan RMSE: Nan

My goal is to have the formula of the surface, like that I can find the third parameter when I know 2 of them.

Thank you

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Answer 1

[Sean de Wolski]

There really isn't a formula for the surface. It's a piecewise linear surface so it's a single formula for a plane at each location of your data making it many formulas altogether.

It sounds like you want to fit a plane or a custom equation to your data so that you can find the coefficients.

[Benjamin]

Ok thank you