Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / control-2.3.52 / @lti / uminus.m

diff --git a/octave_packages/control-2.3.52/@lti/uminus.m b/octave_packages/control-2.3.52/@lti/uminus.m
new file mode 100644 (file)
index 0000000..7e6c4f6
--- /dev/null
+++ b/octave_packages/control-2.3.52/@lti/uminus.m
@@ -0,0 +1,37 @@
+## Copyright (C) 2009   Lukas F. Reichlin
+##
+## This file is part of LTI Syncope.
+##
+## LTI Syncope 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.
+##
+## LTI Syncope 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 LTI Syncope.  If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## Unary minus of LTI object.  Used by Octave for "-sys".
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: September 2009
+## Version: 0.1
+
+function sys = uminus (sys)
+
+  if (nargin != 1)  # prevent sys = uminus (sys1, sys2, sys3, ...)
+    error ("lti: uminus: this is an unary operator");
+  endif
+
+  [p, m] = size (sys);
+
+  out_scl = - eye (p);
+
+  sys = out_scl * sys;
+
+endfunction