Solve a system of differential equations which has blkdiag

I want to solve following equation:

with

Matrices A and C are defined.

I want use ode45 to solve, but I don't know to define matrix B.

function dpdt = control_law(t,xe)
global A C
x = xe(1:2*n,1);
y = xe(2*n+1:end,1);
dxdt = Ax +By (????????)
dydt = C*x;
dpdt = [dxdt;dydt];
end

I tried some of the analysis but to no avail

Answer 1

[Torsten]

x = [1;2;3;4;5;6];
x = reshape(x,2,[]);
B = arrayfun(@(i)squeeze(kron(x(:,i).',eye(2))),1:size(x,2),'UniformOutput',0);
C = blkdiag(B{:})

C = 6×12

1 0 2 0 0 0 0 0 0 0 0 0 0 1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 3 0 4 0 0 0 0 0 0 0 0 0 0 3 0 4 0 0 0 0 0 0 0 0 0 0 0 0 5 0 6 0 0 0 0 0 0 0 0 0 0 5 0 6

Answer 2

[Luca Ferro]

given i as identity with coeherent dimensions to x:

blkdiag(x'.*i)

edit: to create i use the eye(n) function, where n is the dimensions

[Hoang Vu Huy]

Sorry, I don't understand your idea. Please re-explain

Answer 3

[Torsten]

You can't supply it as a global, but only pass it as a function handle:

B = @(x) blkdiag(kron(x.',eye(2)))

Or you define it as

B = blkdiag(kron(x.',eye(2)))

in the function.

[Hoang Vu Huy]

I try but I think it's not true

For example, , that mean

I want to creat matrix , so B equals

But, I run your code B = blkdiag(kron(x.',eye(2))), B equals: