Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / control-2.3.52 / @tf / __zero__.m

diff --git a/octave_packages/control-2.3.52/@tf/__zero__.m b/octave_packages/control-2.3.52/@tf/__zero__.m
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+++ b/octave_packages/control-2.3.52/@tf/__zero__.m
@@ -0,0 +1,37 @@
+## Copyright (C) 2009, 2011   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 -*-
+## Transmission zeros of TF object.
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: October 2009
+## Version: 0.2
+
+function [zer, gain] = __zero__ (sys)
+
+  if (issiso (sys))
+    num = get (sys.num{1});
+    den = get (sys.den{1});
+    zer = roots (num);
+    gain = num(1) / den(1);
+  else
+    warning ("tf: zero: converting to minimal state-space for zero computation of mimo tf");
+    [zer, gain] = zero (ss (sys));
+  endif
+
+endfunction