/usr/share/octave/packages/control-3.0.0/estim.m is in octave-control 3.0.0-2.
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 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | ## Copyright (C) 2009-2015 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 -*-
## @deftypefn {Function File} {@var{est} =} estim (@var{sys}, @var{l})
## @deftypefnx {Function File} {@var{est} =} estim (@var{sys}, @var{l}, @var{sensors}, @var{known})
## Return state estimator for a given estimator gain.
##
## @strong{Inputs}
## @table @var
## @item sys
## @acronym{LTI} model.
## @item l
## State feedback matrix.
## @item sensors
## Indices of measured output signals y from @var{sys}. If omitted, all outputs are measured.
## @item known
## Indices of known input signals u (deterministic) to @var{sys}. All other inputs to @var{sys}
## are assumed stochastic (w). If argument @var{known} is omitted, no inputs u are known.
## @end table
##
## @strong{Outputs}
## @table @var
## @item est
## State-space model of estimator.
## @end table
##
## @strong{Block Diagram}
## @example
## @group
## u +-------+ ^
## +---------------------------->| |-------> y
## | +-------+ + y | est | ^
## u ----+--->| |----->(+)------>| |-------> x
## | sys | ^ + +-------+
## w -------->| | |
## +-------+ | v
## @end group
## @end example
##
## @seealso{kalman, lqe, place}
## @end deftypefn
## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
## Created: November 2009
## Version: 0.3
function est = estim (sys, l, sensors = [], known = [])
if (nargin < 2 || nargin > 4)
print_usage ();
endif
if (! isa (sys, "lti"))
error ("estim: first argument must be an LTI system");
endif
sys = ss (sys); # needed to get stname from tf models
[a, b, c, d, e, tsam] = dssdata (sys, []);
[inn, stn, outn, ing, outg] = get (sys, "inname", "stname", "outname", "ingroup", "outgroup");
if (isempty (sensors))
sensors = 1 : rows (c);
endif
if (ischar (sensors))
sensors = {sensors};
endif
if (ischar (known))
known = {known};
endif
if (iscell (sensors))
tmp = cellfun (@(x) __str2idx__ (outg, outn, x, "out"), sensors(:), "uniformoutput", false);
sensors = vertcat (tmp{:});
endif
if (iscell (known))
tmp = cellfun (@(x) __str2idx__ (ing, inn, x, "in"), known(:), "uniformoutput", false);
known = vertcat (tmp{:});
endif
m = length (known);
n = rows (a);
p = length (sensors);
if (rows (l) != n)
error ("estim: system '%s' has %d states, but the state estimator gain '%s' has %d rows", ...
inputname (1), n, inputname (2), rows (l));
endif
if (columns (l) != p)
error ("estim: estimator gain '%s' has %d columns, but argument 'known' contains %d indices", ...
inputname (2), columns (l), p);
endif
b = b(:, known);
c = c(sensors, :);
d = d(sensors, known);
stname = __labels__ (stn, "xhat");
outname = vertcat (__labels__ (outn(sensors(:)), "yhat"), stname);
inname = vertcat (__labels__ (inn(known(:)), "u"), __labels__ (outn(sensors(:)), "y"));
f = a - l*c;
g = [b - l*d, l];
h = [c; eye(n)];
j = [d, zeros(p, p); zeros(n, m), zeros(n, p)];
## k = e;
est = dss (f, g, h, j, e, tsam);
est = set (est, "inname", inname, "stname", stname, "outname", outname);
endfunction
%!shared m, m_exp
%! sys = ss (-2, 1, 1, 3);
%! est = estim (sys, 5);
%! [a, b, c, d] = ssdata (est);
%! m = [a, b; c, d];
%! m_exp = [-7, 5; 1, 0; 1, 0];
%!assert (m, m_exp, 1e-4);
%!shared m, m_exp
%! sys = ss (-1, 2, 3, 4);
%! est = estim (sys, 5);
%! [a, b, c, d] = ssdata (est);
%! m = [a, b; c, d];
%! m_exp = [-16, 5; 3, 0; 1, 0];
%!assert (m, m_exp, 1e-4);
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