// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) INRIA -
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution.  The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt

function [K,r]=obscont(P,Kc,Kf)
    //Returns the observer-based controller associated with a
    //plant P=[A,B,C,D]. The full-state control gain is Kc and filter
    //gain is Kf. A+B*Kc and A+C*Kf are assumed stable.

    [LHS,RHS]=argn(0)
    [A,B,C,D]=abcd(P);
    K=syslin(P(7),A+B*Kc+Kf*C+Kf*D*Kc,-Kf,Kc)
    if LHS==1 then r=[];return;end
    zro=0*Kc*Kf;I1=eye(Kc*B);I2=eye(C*Kf);
    K=syslin(P(7),A+B*Kc+Kf*C+Kf*D*Kc,[-Kf,B+Kf*D],[Kc;-C-D*Kc],[zro,I1;I2,-D]);
    r=size(D);
endfunction