sysconnect

% -*- texinfo -*-
% @deftypefn {Function File} {@var{clsys} =} sysconnect (@var{sys}, @var{out_idx}, @var{in_idx}, @var{order}, @var{tol})
% Close the loop from specified outputs to respective specified inputs
%
% @strong{Inputs}
% @table @var
% @item   sys
% System data structure.
% @item   out_idx
% @itemx  in_idx
% Names or indices of signals to connect (see @code{sysidx}).
% The output specified by @math{out_idx(ii)} is connected to the input
% specified by @math{in_idx(ii)}.
% @item   order
% logical flag (default = 0)
% @table @code
% @item        0
% Leave inputs and outputs in their original order.
% @item        1
% Permute inputs and outputs to the order shown in the diagram below.
% @end table
% @item     tol
% Tolerance for singularities in algebraic loops, default: 200@code{eps}.
% @end table
%
% @strong{Outputs}
% @table @var
% @item clsys
% Resulting closed loop system.
% @end table
%
% @strong{Method}
%
% @code{sysconnect} internally permutes selected inputs, outputs as shown
% below, closes the loop, and then permutes inputs and outputs back to their
% original order
% @example
% @group
%                  --------------------
%  u_1       ----->|                  |----> y_1
%                  |        sys       |
%          old u_2 |                  |
% u_2* ---->(+)--->|                  |----->y_2
% (in_idx)   ^     --------------------    | (out_idx)
%            |                             |
%            -------------------------------
% @end group
% @end example
% The input that has the summing junction added to it has an * added to
% the end  of the input name.
% @end deftypefn