Subscripted assignment dimension mismatch for dare function ( periodic solution for Riccati equation)

Hi everyone,

Any help on this will be highly appreciated

I have a dynamic system, which I linearized according to different periods. I seek from this system in the form:

xdot (t) = A (t) x + B (t) u

y (t) = C (t) x

to solve the Riccati equation. In the case of a periodic system, I end up with multidimensional matrices. When trying to solve the riccati equation with a "loop for" on the dare function I get the following error: Subscripted assignment dimension mismatch.

A_p(4,4,36)

B_p(4,3,36)

C_p(2,4,36)

R_ipb(3,3,36)

A_p=AMat;
B_p=BMat;
C_p=CMat;

[m,n,p]=size(AMat);
[mb,nb,pb]=size(BMat);

R_ipb = zeros(nb,nb,pb);

 for i=1:p
Q_ipb(:,:,i)=CMat(:,:,i)'*CMat(:,:,i);
 end
 for i=1:pb
 R_ipb(:,:,i)=eye(nb);
 end

 %periodique riccati résolution à chaque pas azimutal
 for i=1:p
[X(:,:,i),K_ipb(:,:,i)]=dare(A_p(:,:,i),B_p(:,:,i),Q_ipb(:,:,i), R_ipb(:,:,i));
 end

I have looked at the documentation about the dare function on mathworks but I don't understand my problem.

Thank you in advance for your answers.

[Rik]

Your output syntax assumes all iterations will result in the same size 2D array. It also assumes you don't have variables with that name, or that they are pre-allocated with the correct size.

[SALIC Tom]

thank you for your answer ! it works.