Regression Analysis.

[therock003]

I want to make kind of a 3d regression and from a set of 3d points (XYZ - Coords) i want to calculate the interpolated plane,that fits best between the set of points.

So far I've only thought of making 3 linear regressions,one on each plane (XY,XZ,YZ) and combining them to create the plane.I don't know if there's an easier,more accurate and better way to do this.

Also what's the precision of the regression equation.it seems like it provides 4 decimals for the a coefficient and 2 for the b constant.Is that good,can i make it provide more accurate equation for the regression it draws?I mean does it use this exact equation or does it display an approximation of the regression it drew?

 

[therock003]

Thanx man,by the way this function is hardcore how come you know about it?Are you working with 3d modelling or something?

 

[pgc01]

Well, if you see it from the point of view of statistics this is just a linear regression.

I'm not working in 3D modelling, although I must say that it must be incredibly interesting as it poses a lot of interesting problems related to light and shadow, texture, smooth curves modelling, modelling with animation, etc. If I had chosen this area I'd surely enjoy it, especially modelling physics or biology processes with animation, like for instance air resistance, or growth of organisms. If you work in this area you surely have your hands full.

 

[therock003]

Well i tried to see it from the point of view of regression but i still had problems.What area of work are you into if i may ask?

I'm just getting my degree as a land surveyor.

That concerned a small photogrammetry part of a road design project i was working on.

I would have had my hands full if i wasnt pointed to that function.

As a sureveyor I basically work with 2d designs, but in planning this i needed to go into some basic 3d and this was part of the calculations along with some photogrametric cordinate sytem transformations.

Math and drafting,you cant go wrong,gotta love these stuff.Excel and AutoCAD,that's what's all about!

Anyway, enough of my bubbling.Take care.

 

[MrExcel]

This old thread is still getting some hits. I ran across a utility from 5DChart that will compute the best fit plane equation using least squares, and to display a 3D regression plane directly in Excel.

Check it out at 5DChart.