/usr/share/octave/packages/control-2.6.2/@iddata/filter.m is in octave-control 2.6.2-1build1.
This file is owned by root:root, with mode 0o644.
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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 | ## 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 -*-
## @deftypefn {Function File} {@var{dat} =} filter (@var{dat}, @var{sys})
## @deftypefnx {Function File} {@var{dat} =} filter (@var{dat}, @var{b}, @var{a})
## Filter output and input signals of dataset @var{dat}.
## The filter is specified either by @acronym{LTI} system @var{sys}
## or by transfer function polynomials @var{b} and @var{a} as described
## in the help text of the built-in filter command. Type @code{help filter}
## for more information.
##
## @strong{Inputs}
## @table @var
## @item dat
## iddata identification dataset containing signals in time-domain.
## @item sys
## @acronym{LTI} object containing the discrete-time filter.
## @item b
## Numerator polynomial of the discrete-time filter.
## Must be a row vector containing the coefficients
## of the polynomial in ascending powers of z^-1.
## @item a
## Denominator polynomial of the discrete-time filter.
## Must be a row vector containing the coefficients
## of the polynomial in ascending powers of z^-1.
## @end table
##
## @strong{Outputs}
## @table @var
## @item dat
## iddata identification dataset with filtered
## output and input signals.
## @end table
##
## @end deftypefn
## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
## Created: August 2012
## Version: 0.1
function dat = filter (dat, b, a = [], si = [])
if (nargin < 2 || nargin > 4)
print_usage ();
endif
if (! isa (dat, "iddata")) # there's at least one iddata set, but not as the first argument
error ("iddata: filter: first argument must be an iddata set");
endif
if (! dat.timedomain)
error ("iddata: filter: require iddata set in time-domain");
endif
if (isa (b, "lti")) # filter (dat, sys)
if (nargin > 3) # filter (dat, sys, si) has at most 3 inputs
print_usage ();
endif
if (! issiso (b))
error ("iddata: filter: second argument must be a SISO LTI system");
endif
si = a; # filter (dat, sys, si)
if (isct (b)) # sys is continuous-time
b = c2d (b, dat.tsam{1}); # does this discretization/tsam make sense?
endif
[b, a] = filtdata (b, "vector"); # convert LTI system to transfer function
elseif (nargin < 3)
print_usage ();
endif
## use Octave's filter function for each experiment
## the fifth argument '1' specifies the dimension in case of datasets with only 1 sample
dat.y = cellfun (@(y) filter (b, a, y, si, 1), dat.y, "uniformoutput", false);
dat.u = cellfun (@(u) filter (b, a, u, si, 1), dat.u, "uniformoutput", false);
endfunction
## TODO: adapt test
%!shared DATD, Z
%! DAT = iddata ({[(1:10).', (1:2:20).'], [(10:-1:1).', (20:-2:1).']}, {[(41:50).', (46:55).'], [(61:70).', (-66:-1:-75).']});
%! DATD = detrend (DAT, "linear");
%! Z = zeros (10, 2);
%!assert (DATD.y{1}, Z, 1e-10);
%!assert (DATD.y{2}, Z, 1e-10);
%!assert (DATD.u{1}, Z, 1e-10);
%!assert (DATD.u{2}, Z, 1e-10);
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