On Fri, Jul 02, 2010 at 11:24:19AM +0200, "Marc Schütz" wrote: > > Distance form: | AG * n0 | ( * being a scalar product ) > > Our distance: | (1, 2) * (-0.8, 0.6) | = | -0.8 + 1.2 | > > > > -> distance: 0.4 > > The length of a vector (a,b) is sqrt(a^2 + b^2), not abs(a+b)! > Thus |(1,2) * (-0.8,0.6)| = |-0.8,1.2| = sqrt(0.64+1.44) = sqrt(2.08) ~ 1.44 > The scalar product (or dot product) of the vectors (1, 2) * (-0.8, 0.6) is -0.8 + 1.2 => 0.4. (And for sure it must be a scalar, that's why it's called scalar product).
You are talking about a cross product, but that's not what we need in the hesse normal form. The second approach with the intersection of the vectors also showed, that 0.4 is the correct distance. The graphical approach which I draw to check my result also showed ~0.5. [1] http://en.wikipedia.org/wiki/Dot_product -- Seid unbequem, seid Sand, nicht Öl im Getriebe der Welt! - Günther Eich ,---------------------------------------------------------------------. | Stephan Plepelits, | | Technische Universität Wien - Studien Informatik & Raumplanung | | Projects: | | > openstreetbrowser.org > couchsurfing.org > tubasis.at > bl.mud.at | | Contact: | | > Mail: [email protected] > Blog: plepe.at > Jabber: [email protected]| | > Twitter: twitter.com/plepe > Wave: [email protected] | `---------------------------------------------------------------------' _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
