Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/control-2.3.52/@lti/subsref.m b/octave_packages/control-2.3.52/@lti/subsref.m
new file mode 100644 (file)
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+++ b/octave_packages/control-2.3.52/@lti/subsref.m
@@ -0,0 +1,60 @@
+## Copyright (C) 2009, 2012   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 -*-
+## Subscripted reference for LTI objects.
+## Used by Octave for "sys = sys(2:4, :)" or "val = sys.prop".
+
+## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
+## Created: September 2009
+## Version: 0.4
+
+function a = subsref (a, s)
+
+  if (numel (s) == 0)
+    return;
+  endif
+
+  switch (s(1).type)
+    case "()"
+      idx = s(1).subs;
+      if (numel (idx) == 2)
+        a = __sys_prune__ (a, idx{1}, idx{2});
+      elseif (numel (idx) == 1)
+        a = __freqresp__ (a, idx{1});  
+      else
+        error ("lti: subsref: need one or two indices");
+      endif
+    case "."
+      fld = s(1).subs;
+      a = get (a, fld);
+      ## warning ("lti: subsref: do not use subsref for development");
+    otherwise
+      error ("lti: subsref: invalid subscript type");
+  endswitch
+  
+  a = subsref (a, s(2:end));
+
+endfunction
+
+
+## lti: subsref
+%!shared a
+%! s = tf ("s");
+%! G = (s+1)*s*5/(s+1)/(s^2+s+1);
+%! a = G(1,1).num{1,1}(1);
+%!assert (a, 5, 1e-4);