Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/quaternion-2.0.0/@quaternion/display.m b/octave_packages/quaternion-2.0.0/@quaternion/display.m
new file mode 100644 (file)
index 0000000..bc63687
--- /dev/null
+++ b/octave_packages/quaternion-2.0.0/@quaternion/display.m
@@ -0,0 +1,63 @@
+## 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 -*-
+## Display routine for quaternions.  Used by Octave internally.
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: May 2010
+## Version: 0.2
+
+function display (q)
+
+  name = inputname(1);
+  s = size (q);
+  
+  if (length (s) == 2 && all (s == 1))  # scalar quaternion
+    w = num2str (q.w, 4);
+    x = __num2str__ (q.x);
+    y = __num2str__ (q.y);
+    z = __num2str__ (q.z);
+    disp ([name, " = ", w, x, "i" y, "j", z, "k"]);
+    disp ("");
+  else                                  # non-scalar quaternion
+    disp ([name, ".w ="]);
+    disp (q.w);
+    disp ("");
+    disp ([name, ".x ="]);
+    disp (q.x);
+    disp ("");
+    disp ([name, ".y ="]);
+    disp (q.y);
+    disp ("");
+    disp ([name, ".z ="]);
+    disp (q.z);
+    disp ("");
+  endif
+
+endfunction
+
+
+function str = __num2str__ (num)
+
+  if (sign (num) == -1)
+    str = " - ";
+  else
+    str = " + ";
+  endif
+  
+  str = [str, num2str(abs (num), 4)];
+
+endfunction