Request: Fit a plane, line etc to a cloud of 3d-points
Being able to work with trivariate data seems as a natural expansion when GeoGebra goes 3D. Creating lists of 3d-points from values in the spreadsheet would be a good start, combined with linear algorithms for fitting pointclouds to either a plane or a 3d-line. Obviously, linear combinations and general fits would be most welcome too. I actually ran in to this problem just now and the nearest thing that will do it seems to be Matlab (and I guess Mathematica, though I can't get Wolfram Alpha to do it). I came across papers on formal solutions in linear algebra by googling "fit plane to 3d pointcloud" but I can't be bothered to do it manually.