Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / signal-1.1.3 / ss2tf.m

diff --git a/octave_packages/signal-1.1.3/ss2tf.m b/octave_packages/signal-1.1.3/ss2tf.m
new file mode 100644 (file)
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+++ b/octave_packages/signal-1.1.3/ss2tf.m
@@ -0,0 +1,62 @@
+## Copyright (C) 1994, 1996, 2000, 2004, 2005, 2007 Auburn University <btenison@eng.auburn.edu>
+## Copyright (C) 2012 Lukas F. Reichlin <lukas.reichlin@gmail.com>
+##
+## 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{num}, @var{den}] =} ss2tf (@var{a}, @var{b}, @var{c}, @var{d})
+## Conversion from transfer function to state-space.
+## The state space system:
+## @iftex
+## @tex
+## $$ \dot x = Ax + Bu $$
+## $$ y = Cx + Du $$
+## @end tex
+## @end iftex
+## @ifinfo
+## @example
+##       .
+##       x = Ax + Bu
+##       y = Cx + Du
+## @end example
+## @end ifinfo
+##
+## is converted to a transfer function:
+## @iftex
+## @tex
+## $$ G(s) = { { \rm num }(s) \over { \rm den }(s) } $$
+## @end tex
+## @end iftex
+## @ifinfo
+## @example
+##
+##                 num(s)
+##           G(s)=-------
+##                 den(s)
+## @end example
+## @end ifinfo
+##
+## @end deftypefn
+
+## Author: R. Bruce Tenison <btenison@eng.auburn.edu>
+
+function [num, den] = ss2tf (varargin)
+
+  if (nargin == 0)
+    print_usage ();
+  endif
+
+  [num, den] = tfdata (ss (varargin{:}), "vector");
+
+endfunction