Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!news.swapon.de!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Axel Berger Newsgroups: comp.graphics.apps.gnuplot Subject: Re: Fit 3D Line to data Date: Sat, 28 Feb 2015 03:02:25 +0100 Lines: 9 Message-ID: <54F121B1.43E0C8FD@B.Maus.De> References: <68e9ed33-a7ef-4106-8730-151263df2011@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: individual.net E+i6PAdyxld+rExZHX/jjwqYqf+wCYVrpejA1181ts27CWv+NL Cancel-Lock: sha1:H64FF7UBy+ZTWBNgeADPpdUZyyo= X-Mailer: Mozilla 4.8 [en] (Win98; U) X-Accept-Language: en,de,nl,es,fr Xref: csiph.com comp.graphics.apps.gnuplot:2800 Karl wrote: > derive the minimum distance d(x,y,z) of a point xyz from that line, If that was what what a 2D regression did, it would be obvious how to generalise to 3D. But it doesn't. It minmizes the squares of the y-distances for given x values, which at very steep gradients is quite different from the distance between points and line. Axel