/usr/share/octave/packages/control-2.6.2/dss.m is in octave-control 2.6.2-1build1.
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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | ## 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{sys} =} dss (@var{sys})
## @deftypefnx {Function File} {@var{sys} =} dss (@var{d})
## @deftypefnx {Function File} {@var{sys} =} dss (@var{a}, @var{b}, @var{c}, @var{d}, @var{e}, @dots{})
## @deftypefnx {Function File} {@var{sys} =} dss (@var{a}, @var{b}, @var{c}, @var{d}, @var{e}, @var{tsam}, @dots{})
## Create or convert to descriptor state-space model.
##
## @strong{Inputs}
## @table @var
## @item sys
## @acronym{LTI} model to be converted to state-space.
## @item a
## State matrix (n-by-n).
## @item b
## Input matrix (n-by-m).
## @item c
## Output matrix (p-by-n).
## @item d
## Feedthrough matrix (p-by-m).
## @item e
## Descriptor matrix (n-by-n).
## @item tsam
## Sampling time in seconds. If @var{tsam} is not specified,
## a continuous-time model is assumed.
## @item @dots{}
## Optional pairs of properties and values.
## Type @command{set (dss)} for more information.
## @end table
##
## @strong{Outputs}
## @table @var
## @item sys
## Descriptor state-space model.
## @end table
##
## @strong{Option Keys and Values}
## @table @var
## @item 'a', 'b', 'c', 'd', 'e'
## State-space matrices. See 'Inputs' for details.
##
## @item 'stname'
## The name of the states in @var{sys}.
## Cell vector containing strings for each state.
## Default names are @code{@{'x1', 'x2', ...@}}
##
## @item 'scaled'
## Logical. If set to true, no automatic scaling is used,
## e.g. for frequency response plots.
##
## @item 'tsam'
## Sampling time. See 'Inputs' for details.
##
## @item 'inname'
## The name of the input channels in @var{sys}.
## Cell vector of length m containing strings.
## Default names are @code{@{'u1', 'u2', ...@}}
##
## @item 'outname'
## The name of the output channels in @var{sys}.
## Cell vector of length p containing strings.
## Default names are @code{@{'y1', 'y2', ...@}}
##
## @item 'ingroup'
## Struct with input group names as field names and
## vectors of input indices as field values.
## Default is an empty struct.
##
## @item 'outgroup'
## Struct with output group names as field names and
## vectors of output indices as field values.
## Default is an empty struct.
##
## @item 'name'
## String containing the name of the model.
##
## @item 'notes'
## String or cell of string containing comments.
##
## @item 'userdata'
## Any data type.
## @end table
##
## @strong{Equations}
## @example
## @group
## .
## E x = A x + B u
## y = C x + D u
## @end group
## @end example
##
## @seealso{ss, tf}
## @end deftypefn
## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
## Created: September 2010
## Version: 0.1
function sys = dss (varargin)
switch (nargin)
case {0, 1} # static gain (dss (5)) or empty (useful for "set (dss)")
sys = ss (varargin{:});
case {2, 3, 4}
print_usage ();
otherwise # general case
sys = ss (varargin{[1:4, 6:end]}, "e", varargin{5});
endswitch
endfunction
## NOTE: The author prefers "dss (e, a, b, c, d)" since we write
## .
## E x = A x + B u, y = C x + D u
##
## but this would break compatibility to a widespread
## commercial implementation of the octave language.
## There's no way to tell e and d apart if n = m = p.
|