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%2Finv.m;fp=octave_packages%2Fquaternion-2.0.0%2F%40quaternion%2Finv.m;h=7aafaf0e6363bdf250c0d5496d7c866d09c2f6c1;hp=0000000000000000000000000000000000000000;hb=f5f7a74bd8a4900f0b797da6783be80e11a68d86;hpb=1705066eceaaea976f010f669ce8e972f3734b05

diff --git a/octave_packages/quaternion-2.0.0/@quaternion/inv.m b/octave_packages/quaternion-2.0.0/@quaternion/inv.m
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+## Copyright (C) 2010, 2011   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 <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{qinv} =} inv (@var{q})
+## Return inverse of a quaternion.
+## @end deftypefn
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: May 2010
+## Version: 0.2
+
+function a = inv (a)
+
+  if (nargin != 1)
+    print_usage ();
+  endif
+
+  if (isscalar (a.w))
+    norm2 = norm2 (a);
+    a.w = a.w / norm2;
+    a.x = -a.x / norm2;
+    a.y = -a.y / norm2;
+    a.z = -a.z / norm2;
+  else
+    ## TODO: quaternion arrays
+    error ("quaternion: inv: implemented for scalar quaternions only");
+  endif
+
+endfunction