How can i solve Algebraic Ricatti Equation for SDRE controller?

I have a model in simulink. I use SDRE controller for that model . I can obtain SDC matrices(A(x) and B(x)) by matlab function in simulink . One of the example in simulink matlab function is :

 function P  = fcn(u,w)
 %#codegen

 B = [ 0 2  2 0 ;
    1  0 0 3  ; 
    0 4 5 0 ;
    0 0 3 0 ; 
    0 4 0 0 ] ;

 A = [2  0  4 u  0 ; 
          0 5 0 0 0 ;
          6 0 7 w 0 ;    1 0 0 0 0 ; 0 1 0 0 0 ] ; 

 Q= diag([0.6 0.6 0.6 2.6 0.5]);
 R= diag([0.00001 1000 1000 1000]); 

    n = size(A,1);

    P = zeros(n,n);

    H = [A -(B/R)*B'; -Q -A'];

    [T,L] = eig(H);

    lambda = diag(L);
    ord_lambda = zeros(1,2*n);
    for k = 1 : 2*n;
        if real(lambda(k)) < 0
            ord_lambda(k) = -1;
        elseif real(lambda(k)) > 0
            ord_lambda(k) = 1;
        else
            %disp('!!!');
        end
    end

    [~, ord_index] = sort(ord_lambda, 'descend');

    T_ord = T(:,ord_index);

    T22 = T_ord(n+1:2*n,n+1:2*n);
    T12 = T_ord(1:n,n+1:2*n);

    P = real(T22/T12);

[burak ergocmen]

1. The ARE can be solved by some methods .These are iterative and numerical ways. Iterative is the best but numerical is also work well. Some numerical example : Schur decomposition of Hamiltonian matrix , Spectral Factorization Some Iterative example : Matrix sign function 2. For real time application of solving algebraic ricatti equation for SDRE controller there are some ways one of that is using S-function (write codes in C programming and use it in the simulink block). There is a really good thesis about that, also there is C codes in thesis : "ANALYSIS AND REAL-TIME IMPLEMENTATION OF STATE-DEPENDENT RICCATI EQUATION CONTROLLED SYSTEMS-EVRIN BILGE ERDEM " another way is using matlab function in Simulink environment . Some functions does not work but i found one of that which is working but some calculation problems which about re ordering schur decomposition (all eigenvalues have to be in the upper triangle of the schur matrix). I post it in here because "[U_ordered,S_ordered] = ordschur(U,S,'lhp')" code does not work in script.So if anybody have an idea pls post it in here These matlab codes are about schur decomposition of hamiltonian matrix . A and B can easily convertible to SDC matrices which shows the system dynamics

function y = fcn(x1,x2)
A = [x1 x2; x1 x2];
B = [2; 1];
C = eye(2);
D = [0; 0];
Q = [1 1; 3 0];
R = [3];

H = [A -(B*inv(R)*B'); -Q -A'];

[U, S] = schur(H);

[m,n] = size(U);
U11 = U(1:(m/2), 1:(n/2));
U21 = U((m/2+1):m, 1:(n/2));

P = U21*inv(U11) ;

y = P;

[Victory Friday]

Please sir, is there a way out in ordering the eigenvalues for script?