saving a 3D array into a 2d array for each iteration in for loop

Suppose that I have generated a code to solve a nonlinear differential equation.My output in this equation is a 3D array.I want to store the third dimension of this 3D array(which is an n by 2 matrix itselft) into an n by 2 matrix in a for loop for each iteration.What should I do?.Note that my results is stored in 3D array matrix of X

function xDot = of(x,g,L,u)

    xDot = zeros(2,1);
    
    xDot(1) = x(2);
    xDot(2) = ((g./L)*sin(x(1)))+u;

end

And the following is my main script:

clc;
clear;close all;


%% Solve The Nonlinear Equation

L = 1;
g = 9.81;

h = 0.25;
t = [0:h:4];
A = [0 1;(g/L) 0];
B =[0 1]';
Ics = [pi,0;pi/2 0;pi/5 0;0.001 0;pi 0.5;pi/2 0.5;pi/5 0.5;0.001 0.5];
Poles = eig(A);     %Poles Of Closed LOop System
R = 0.001;
Q = eye(2);
K = lqr(A,B,Q,R);

u = @(x)-K*(x);

X = zeros(numel(t), size(Ics, 2), size(Ics, 1)); % initialize the 3D array 

for i = 1:size(Ics,1)
    [~, X(:, :, i)] = ode45(@(t, x)of(x, g, L, u(x)), t, Ics(i, :));
end

Answer 1

[Deepak]

Hi @Mhmmd Sjj,

To my understanding, you have generated a non-linear differential equation and stored the output in a 3D array. Now, you want to store the third dimension of the array (which is itself an n by 2 matrix) in a different variable in each iteration of a for loop.

To do this task, we can iterate over the third dimension of the 3D array with the help of a for loop. Then, we can fetch the third dimension from the array by doing array indexing with the help of the colon (:) operator. Finally, we can process the n-by-2 matrix as needed.

Here is the MATLAB code that addresses this task:

for i = 1:size(X, 3)
    n_by_2_matrix = X(:, :, i);
    % Process n_by_2_matrix as needed
    disp(['Iteration ', num2str(i)]);
    disp(n_by_2_matrix);
end

Attaching the documentation of Array indexing in MATLAB for reference:

https://www.mathworks.com/help/matlab/math/array-indexing.html

I hope this helps to resolve your issue.