This file is indexed.

/usr/share/octave/packages/control-3.0.0/initial.m is in octave-control 3.0.0-5.

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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
## 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} {} initial (@var{sys}, @var{x0})
## @deftypefnx{Function File} {} initial (@var{sys1}, @var{sys2}, @dots{}, @var{sysN}, @var{x0})
## @deftypefnx{Function File} {} initial (@var{sys1}, @var{'style1'}, @dots{}, @var{sysN}, @var{'styleN'}, @var{x0})
## @deftypefnx{Function File} {} initial (@var{sys1}, @dots{}, @var{x0}, @var{t})
## @deftypefnx{Function File} {} initial (@var{sys1}, @dots{}, @var{x0}, @var{tfinal})
## @deftypefnx{Function File} {} initial (@var{sys1}, @dots{}, @var{x0}, @var{tfinal}, @var{dt})
## @deftypefnx{Function File} {[@var{y}, @var{t}, @var{x}] =} initial (@var{sys}, @var{x0})
## @deftypefnx{Function File} {[@var{y}, @var{t}, @var{x}] =} initial (@var{sys}, @var{x0}, @var{t})
## @deftypefnx{Function File} {[@var{y}, @var{t}, @var{x}] =} initial (@var{sys}, @var{x0}, @var{tfinal})
## @deftypefnx{Function File} {[@var{y}, @var{t}, @var{x}] =} initial (@var{sys}, @var{x0}, @var{tfinal}, @var{dt})
## Initial condition response of state-space model.
## If no output arguments are given, the response is printed on the screen.
##
## @strong{Inputs}
## @table @var
## @item sys
## State-space model.
## @item x0
## Vector of initial conditions for each state.
## @item t
## Optional time vector.  Should be evenly spaced.  If not specified, it is calculated
## by the poles of the system to reflect adequately the response transients.
## @item tfinal
## Optional simulation horizon.  If not specified, it is calculated by
## the poles of the system to reflect adequately the response transients.
## @item dt
## Optional sampling time.  Be sure to choose it small enough to capture transient
## phenomena.  If not specified, it is calculated by the poles of the system.
## @item 'style'
## Line style and color, e.g. 'r' for a solid red line or '-.k' for a dash-dotted
## black line.  See @command{help plot} for details.
## @end table
##
## @strong{Outputs}
## @table @var
## @item y
## Output response array.  Has as many rows as time samples (length of t)
## and as many columns as outputs.
## @item t
## Time row vector.
## @item x
## State trajectories array.  Has @code{length (t)} rows and as many columns as states.
## @end table
##
## @strong{Example}
## @example
## @group
##                    .
## Continuous Time:   x = A x ,   y = C x ,   x(0) = x0
##
## Discrete Time:   x[k+1] = A x[k] ,   y[k] = C x[k] ,   x[0] = x0
## @end group
## @end example
##
## @seealso{impulse, lsim, step}
## @end deftypefn

## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
## Created: October 2009
## Version: 1.0

function [y_r, t_r, x_r] = initial (varargin)

  if (nargin < 2)
    print_usage ();
  endif

  [y, t, x] = __time_response__ ("initial", varargin, nargout);

  if (nargout)
    y_r = y{1};
    t_r = t{1};
    x_r = x{1};
  endif

endfunction


%!shared initial_c, initial_c_exp, initial_d, initial_d_exp
%!
%! A = [ -2.8    2.0   -1.8
%!       -2.4   -2.0    0.8
%!        1.1    1.7   -1.0 ];
%!
%! B = [ -0.8    0.5    0
%!        0      0.7    2.3
%!       -0.3   -0.1    0.5 ];
%!
%! C = [ -0.1    0     -0.3
%!        0.9    0.5    1.2
%!        0.1   -0.1    1.9 ];
%!
%! D = [ -0.5    0      0
%!        0.1    0      0.3
%!       -0.8    0      0   ];
%!
%! x_0 = [1, 2, 3];
%!
%! sysc = ss (A, B, C, D);
%!
%! [yc, tc, xc] = initial (sysc, x_0, 0.2, 0.1);
%! initial_c = [yc, tc, xc];
%!
%! sysd = c2d (sysc, 2);
%!
%! [yd, td, xd] = initial (sysd, x_0, 4);
%! initial_d = [yd, td, xd];
%!
%! ## expected values computed by the "dark side"
%!
%! yc_exp = [ -1.0000    5.5000    5.6000
%!            -0.9872    5.0898    5.7671
%!            -0.9536    4.6931    5.7598 ];
%!
%! tc_exp = [  0.0000
%!             0.1000
%!             0.2000 ];
%!
%! xc_exp = [  1.0000    2.0000    3.0000
%!             0.5937    1.6879    3.0929
%!             0.2390    1.5187    3.0988 ];
%!
%! initial_c_exp = [yc_exp, tc_exp, xc_exp];
%!
%! yd_exp = [ -1.0000    5.5000    5.6000
%!            -0.6550    3.1673    4.2228
%!            -0.5421    2.6186    3.4968 ];
%!
%! td_exp = [  0
%!             2
%!             4 ];
%!
%! xd_exp = [  1.0000    2.0000    3.0000
%!            -0.4247    1.5194    2.3249
%!            -0.3538    1.2540    1.9250 ];
%!
%! initial_d_exp = [yd_exp, td_exp, xd_exp];
%!
%!assert (initial_c, initial_c_exp, 1e-4)
%!assert (initial_d, initial_d_exp, 1e-4)