size mismatch in assigning values to a matrice

hey i want to run this but it keeps erroring on mismatching size for F(:,:,i):

Unable to perform assignment because the size of

the left side is 1-by-2 and the size of the right

side is 2-by-2.

and as I check the equation on F, the right side seems a 1-by-2 theoritically

clc;clear all;close all;

A=[0.9974 0.0539;-0.1078 .1591];
B=[0.0013 0.0539]';
H=zeros(2);
Q=[0.25 0;0 0.05];
R=0.05;
[K,S,e]=dlqr(A,B,Q,R);
F=zeros(1,2,200);
P=zeros(2,2,200);
for i=200:-1:2
    P(:,:,1)=H;
    F(:,:,1)=[0 0];
F(:,:,i)= -(B'.*P(:,:,i-1).*A).*inv(R+B'.*P(:,:,i-1).*B);
   P(:,:,i)=(A+B.*F(:,:,i))'.*P(:,:,i-1).*(A+B.*F(:,:,i))+((F(:,:,i))'.*R.*F(i))+Q;
end

Answer 1

[KSSV]

You need to initiliaze the matrices properly.

A=[0.9974 0.0539;-0.1078 .1591];
B=[0.0013 0.0539]';
H=zeros(2);
Q=[0.25 0;0 0.05];
R=0.05;
[K,S,e]=dlqr(A,B,Q,R);
F=zeros(2,2,200);   % <--- change here 
P=zeros(2,2,200);
for i=200:-1:2
    P(:,:,1)=H;
    % F(:,:,1)=[0 0];  % <-- this is not required 
    F(:,:,i)= -(B'.*P(:,:,i-1).*A).*inv(R+B'.*P(:,:,i-1).*B);
    P(:,:,i)=(A+B.*F(:,:,i))'.*P(:,:,i-1).*(A+B.*F(:,:,i))+((F(:,:,i))'.*R.*F(i))+Q;
end

[Rik]

The P line in the loop can also be removed.