# how to iterate a matrix for multiple times

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BOWEN LI on 27 Jun 2019
Commented: BOWEN LI on 27 Jun 2019
Hi
I have a matrix, let's say, a random 5x5 matrix. In time period 1, it is a 5x5 random matrix, in time period 2, all element in the matrix are multiplied by 2 (a number), then in time period 3, all elements in time period 2 multiplied by 2 agian, so on and so forth until time period 30.
Actually this is a small part of my research, but i just begin working on Matlab so i am so confused with this step. Thank you so much for answering this question for me!

James Tursa on 27 Jun 2019
E.g., here is a possible outline
n = 30; % the number of iterations
M = rand(5,5); % some initial matrix
for k=1:n
M = 2*M; % or some other function involving M
end
If you need to save all the intermediate results, then something like this:
n = 30; % the number of iterations
M = zeros(5,5,n+1);
M(:,:,1) = rand(5,5); % some initial matrix
for k=2:n+1
M(:,:,k) = 2*M(:,:,k-1); % or some other function involving M(:,:,k-1)
end
BOWEN LI on 27 Jun 2019
May I ask a similar one in which the matrix are filled with binary variables, and in each iteration i want to get a new binary matrix with the same size.
The way I made the binary matrix is by using the "optimvar" that i want to use the binary matrix as my decision variable in my optimization problem. For example "y" is the binary matrix i want, and "y"=optimvar('y', 'a','b','Type','integer','LowerBound',0,'UpperBound',1)
'a' is ranging from 0-30, and 'b' is ranging from 0-30 also.