Is there a “queue” in MATLAB?

Question

I want to convert a recursive function to a iterative one. What I normally do is, I initialize a queue, put the first job into queue. Then in a while loop I consume

Answer 1

In the case where you need a queue only to store vectors (or scalars), then it is not difficult to use a matrix along with the circshift() function to implement a basic queue with a fixed length.

% Set the parameters of our queue
n = 4; % length of each vector in queue
max_length = 5;

% Initialize a queue of length of nx1 vectors 
queue = NaN*zeros(n, max_length);
queue_length = 0;

To push:

queue = circshift(queue, 1, 2); % Move each column to the right
queue(:,1) = rand(n, 1); % Add new vector to queue
queue_length = min(max_length, queue_length + 1); 

To pop:

result = queue(:,last)
queue(:, last) = NaN;
queue_length = max(1, queue_length - 1);