function flagc=qctrb(a,b)
% 確定狀態(A,B)對的可控性

% Copyright 2001-2002 ECUST. 
%   $Revision: 1.2 $  $Date: 2002/02/21 08:01:11 $

S=ctrb(a,b);nc=rank(S);n=length(a);
if n==nc,flagc='system is completely state controllable';
else flagc='system is not completely state controllable';end;