X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fquaternion-2.0.0%2F%40quaternion%2Fmtimes.m;fp=octave_packages%2Fquaternion-2.0.0%2F%40quaternion%2Fmtimes.m;h=8252f08a0d735dab899574438c156b94e3bb5301;hp=0000000000000000000000000000000000000000;hb=c880e8788dfc484bf23ce13fa2787f2c6bca4863;hpb=1705066eceaaea976f010f669ce8e972f3734b05 diff --git a/octave_packages/quaternion-2.0.0/@quaternion/mtimes.m b/octave_packages/quaternion-2.0.0/@quaternion/mtimes.m new file mode 100644 index 0000000..8252f08 --- /dev/null +++ b/octave_packages/quaternion-2.0.0/@quaternion/mtimes.m @@ -0,0 +1,43 @@ +## Copyright (C) 2010 Lukas F. Reichlin +## +## This program is free software: you can redistribute it and/or modify +## it under the terms of the GNU General Public License as published by +## the Free Software Foundation, either version 3 of the License, or +## (at your option) any later version. +## +## This program is distributed in the hope that it will be useful, +## but WITHOUT ANY WARRANTY; without even the implied warranty of +## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +## GNU General Public License for more details. +## +## You should have received a copy of the GNU General Public License +## along with this program. If not, see . + +## -*- texinfo -*- +## Matrix multiplication of two quaternions. Used by Octave for "q1 * q2". + +## Author: Lukas Reichlin +## Created: May 2010 +## Version: 0.1 + +function a = mtimes (a, b) + + if (! isa (a, "quaternion")) + a = quaternion (a); + endif + + if (! isa (b, "quaternion")) + b = quaternion (b); + endif + + w = a.w*b.w - a.x*b.x - a.y*b.y - a.z*b.z; + x = a.y*b.z - a.z*b.y + a.w*b.x + a.x*b.w; + y = a.z*b.x - a.x*b.z + a.w*b.y + a.y*b.w; + z = a.x*b.y - a.y*b.x + a.w*b.z + a.z*b.w; + + a.w = w; + a.x = x; + a.y = y; + a.z = z; + +endfunction