Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / quaternion-2.0.0 / @quaternion / exp.m

diff --git a/octave_packages/quaternion-2.0.0/@quaternion/exp.m b/octave_packages/quaternion-2.0.0/@quaternion/exp.m
new file mode 100644 (file)
index 0000000..97ecce1
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+++ b/octave_packages/quaternion-2.0.0/@quaternion/exp.m
@@ -0,0 +1,40 @@
+## Copyright (C) 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{qexp} =} exp (@var{q})
+## Exponential of a quaternion.
+## @end deftypefn
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: November 2011
+## Version: 0.1
+
+function q = exp (q)
+
+  if (nargin != 1)
+    print_usage ();
+  endif
+
+  normv = normv (q);
+  exps = exp (q.w);
+  sinv = sin (normv);
+
+  q.w = exps .* cos (normv);    
+  q.x = exps .* (q.x ./ normv) .* sinv;
+  q.y = exps .* (q.y ./ normv) .* sinv;
+  q.z = exps .* (q.z ./ normv) .* sinv;
+
+endfunction