/usr/share/octave/packages/control-2.6.2/@tf/__sys_inverse__.m is in octave-control 2.6.2-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 | ## Copyright (C) 2009-2014 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 -*-
## Inversion of TF models.
## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
## Created: October 2009
## Version: 0.2
function sys = __sys_inverse__ (sys)
nvec = size (sys);
num = sys.num;
den = sys.den;
if (all (nvec == 1)) # SISO
if (num{1,1} == 0) # catch case num = 0
sys.num(1,1) = tfpoly (0);
sys.den(1,1) = tfpoly (1);
else
sys.num = den;
sys.den = num;
endif
elseif (all (nvec == 2)) # 2x2 MIMO
sys.num(1,1) = -den{1,1}*den{1,2}*den{2,1}*num{2,2};
sys.num(1,2) = den{1,1}*den{2,1}*den{2,2}*num{1,2};
sys.num(2,1) = den{1,1}*den{1,2}*den{2,2}*num{2,1};
sys.num(2,2) = -den{1,2}*den{2,1}*den{2,2}*num{1,1};
sys.den(:) = den{1,1}*den{2,2}*num{1,2}*num{2,1} - den{1,2}*den{2,1}*num{1,1}*num{2,2};
else
## I've calculated 3x3 systems with sage but the formula is quite long
[num, den] = tfdata (inv (ss (sys)), "tfpoly");
sys.num = num;
sys.den = den;
endif
endfunction
|