Help to create a loop

Hi everybody, Can anybody help me to write a loop that achieves the same result as this code?:

%
G(:,:,1)=kron(J*A'^0,Phi(:,:,1));
G(:,:,2)=kron(J*A'^1,Phi(:,:,1))+kron(J*A'^0,Phi(:,:,2));
G(:,:,3)=kron(J*A'^2,Phi(:,:,1))+kron(J*A'^1,Phi(:,:,2))+kron(J*A'^0,Phi(:,:,3));
G(:,:,4)=kron(J*A'^3,Phi(:,:,1))+kron(J*A'^2,Phi(:,:,2))+kron(J*A'^1,Phi(:,:,3))+kron(J*A'^0,Phi(:,:,4));
%

and so on, until G(:,:,9). Where

%
J=[eye(3) zeros(3)]
%

A =

-0.32   0.15  0.96   -0.16  0.15  0.93
 0.04  -0.15  0.29  0.05  0.02   -0.01
-0.00   0.22  -0.26  0.03  0.35   -0.02
 1   0  0  0  0  0
 0   1  0  0  0  0
 0   0  1  0  0  0

and Phi is in attached.

Thanks for your help

best,

Answer 1

[Matthew Eicholtz]

Here is one potential approach:

G = zeros(9,18,9); %seems to me to be the size you need to preallocate
for ii=1:9
  for jj=ii-1:-1:0
    G(:,:,ii) = G(:,:,ii) + kron(J*A'^jj, Phi(:,:,ii-jj));
  end
end

[Luciano Campos]

Thanks Matt! It Works!

best,

Answer 2

[Guillaume]

I don't see where the difficulty is:

for page = 1:9
  gsum = [];
  for iter = 1:page
     gsum = gsum + kron(J*A'^(page-iter), Phi(:,:,iter));
  end
  G(:, :, page) = gsum;
end

There may be a way to vectorise the inner loop but I've not tried to understand what the code is doing.

[Luciano Campos]

Thanks for your help, Guillaume.

best,