%% x1-centric
uA = A;
uB = B;

%% transformation

% extract E and F matrix from A matrix
e11=uA(1,1);
E1x=[uA(1,3) uA(1,5)];
Ex1=[uA(3,1);uA(5,1)];
Exx=[uA(3,3) uA(3,5);
     uA(5,3) uA(5,5)];

f11=uA(1,2);
F1x=[uA(1,4) uA(1,6)];
Fx1=[uA(3,2);uA(5,2)];
Fxx=[uA(3,4) uA(3,6);
     uA(5,4) uA(5,6)];
 
b1=uB(1,1);
Bx=[uB(3,1);uB(5,1)];


xE = [e11 E1x; Ex1 Exx];
xF = [f11 F1x; Fx1 Fxx];
xB = [b1; Bx];

% transformation
tE = Exx - E1x*Bx/b1;
tF = Fxx - F1x*Bx/b1;


% denominator of G_2
syms s
alpha_2 = det(s^2*eye(2) - tE*s - tF);

% find roots of  G_2
ro = roots(double(sym2poly(alpha_2)))

% choose one root
delay_tx1c = pi/imag(ro(1))





