Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/quaternion-2.0.0/@quaternion/subsasgn.m b/octave_packages/quaternion-2.0.0/@quaternion/subsasgn.m
new file mode 100644 (file)
index 0000000..8777b5c
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+++ b/octave_packages/quaternion-2.0.0/@quaternion/subsasgn.m
@@ -0,0 +1,64 @@
+## 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 -*-
+## Subscripted assignment for quaternions.
+## Used by Octave for "q.key = value".
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: November 2011
+## Version: 0.2
+
+function q = subsasgn (q, idx, val)
+
+  switch (idx(1).type)
+    case "()"                                                    # q(...) = val
+      if (length (idx(1).subs) == 1 && isa (val, "quaternion"))  # required by horzcat, vertcat, cat, ...
+        q(idx(1).subs{:}) = val;                                 # q = cellfun (@quaternion, varargin)
+      else                                                       # general case
+        val = quaternion (val);
+        w = subsasgn (q.w, idx, val.w);
+        x = subsasgn (q.x, idx, val.x);
+        y = subsasgn (q.y, idx, val.y);
+        z = subsasgn (q.z, idx, val.z);
+        q = quaternion (w, x, y, z);
+      endif
+
+    case "."                                                     # q.w = val
+      if (! is_real_array (val))
+        error ("quaternion: subsasgn: invalid argument type, require real array");
+      endif
+      if (! size_equal (subsref (q.w, idx(2:end)), val))
+        error ("quaternion: subsasgn: invalid argument size [%s], require dimensions [%s]", \
+               num2str (size (val), "%d "), num2str (size (subsref (q.w, idx(2:end))), "%d "));
+      endif
+      switch (tolower (idx(1).subs))
+        case {"w", "s"}
+          q.w = subsasgn (q.w, idx(2:end), val);
+        case {"x", "i"}
+          q.x = subsasgn (q.x, idx(2:end), val);
+        case {"y", "j"}
+          q.y = subsasgn (q.y, idx(2:end), val);
+        case {"z", "k"}
+          q.z = subsasgn (q.z, idx(2:end), val);
+        otherwise
+          error ("quaternion: subsasgn: invalid subscript name '%s'", idx(1).subs);
+      endswitch
+
+    otherwise
+      error ("quaternion: subsasgn: invalid subscript type '%s'", idx(1).type);
+  endswitch
+
+endfunction