Tag Archives: Linear regression

Fitting Plane to Point Cloud – Hands on

In my last post i described how to get the equations for fitting a plane to a given pointcloud. Now lets put them into some sample code. I will use the same notation as in the previous post.

When i first started with the optimization, i thought about distinguishing the different cases by Txx != 0. I already worked out the math for the case Txx == 0 etc. And then i started testing with real world data. Random points which are approximatly on a plane. The sad part is: Even with a pointcloud where Txx should be approximatly zero it wasnt close enough to make a valid decision. (And yes i know that comparing a float with 0 is not the way you do it) So sometimes the algorithm ended in the Txx != 0 case, setting c = 1 where c should actually be 0, but because of the unequally distributed values, it wasnt… Continue reading Fitting Plane to Point Cloud – Hands on

3D linear regression: Fitting planes on Pointclouds

Time for a math-post.

Linear regression, or fitting a line on a list of 2D points, is quite common with lots of code samples. But once you want to go further torwards more dimensions, there are no examples whatsoever… You find the wikipedia article about the theory, but eveything is in general terms. Its about calculating the invers of a matrix and lots of stuff that you dont want to do when thinking about performance. Continue reading 3D linear regression: Fitting planes on Pointclouds