function [at,bt,ct,dt] = ss2ss(a,b,c,d,t)
%SS2SS  Change of state coordinates for state-space systems.
%
%     SYS = SS2SS(SYS,T) performs the similarity transformation z = Tx 
%     on the state vector x of the system SYS.  The resulting state-space 
%     system is described by:
%
%                    .       -1        
%                    z = [TAT  ] z + [TB] u
%                           -1
%                    y = [CT   ] z + D u
%
%     (Respectively,
%
%                -1  .       -1        
%            [TET  ] z = [TAT  ] z + [TB] u
%                           -1
%                    y = [CT   ] z + D u
%
%     in the descriptor case).
%
%     See also   CANON, AUGSTATE, SSBAL, BALREAL.

% Old help 
%warning(['This calling syntax for ' mfilename ' will not be supported in the future.'])
%SS2SS Similarity transform.
%	[At,Bt,Ct,Dt] = SS2SS(A,B,C,D,T) performs the similarity 
%	transform z = Tx.  The resulting state space system is:
%
%		.       -1        
%		z = [TAT  ] z + [TB] u
%		       -1
%		y = [CT   ] z + Du
%
%	See also: CANON,BALREAL and BALANCE.

%	Clay M. Thompson  7-3-90
%	Copyright (c) 1986-97 by The MathWorks, Inc.
%	$Revision: 1.3 $  $Date: 1997/04/09 00:45:33 $


error(nargchk(5,5,nargin));
error(abcdchk(a,b,c,d));

at = t*a/t; bt = t*b; ct = c/t; dt = d;
