sysdup

% -*- texinfo -*-
% @deftypefn {Function File} {@var{retsys} =} sysdup (@var{asys}, @var{out_idx}, @var{in_idx})
% Duplicate specified input/output connections of a system
%
% @strong{Inputs}
% @table @var
% @item asys
% system data structure
% @item out_idx
% @itemx in_idx
% indices or names of desired signals (see @code{sigidx}).
% duplicates are made of @code{y(out_idx(ii))} and @code{u(in_idx(ii))}.
% @end table
%
% @strong{Output}
% @table @var
% @item retsys
% Resulting closed loop system:
% duplicated i/o names are appended with a @code{'+'} suffix.
% @end table
%
% @strong{Method}
%
% @code{sysdup} creates copies of selected inputs and outputs as
% shown below.  @var{u1}, @var{y1} is the set of original inputs/outputs, and
% @var{u2}, @var{y2} is the set of duplicated inputs/outputs in the order 
% specified in @var{in_idx}, @var{out_idx}, respectively
% @example
% @group
%           ____________________
% u1  ----->|                  |----> y1
%           |       asys       |
% u2 ------>|                  |----->y2
% (in_idx)  -------------------- (out_idx)
% @end group
% @end example
% @end deftypefn