I run this but its given me issues. Can someone assist

```matlab % Step 1: Define variables and parameters eta = 1; % Initial value of eta epsilon = 1e-5; % Convergence condition L = 3; % L value

% Step 2: Loop for iteration eta_diff = []; % Store absolute difference between eta_n+1 and eta_n iteration = 0; % Initialize iteration counter

while true iteration = iteration + 1;

    % Calculate values using the given equation
    omega = 1 / (iteration * (iteration + 1));
    zeta = 1 / (iteration + 1);
    vartheta = 1 / (iteration + 1);
    psi_eta = eta / 2;
    A = L * eta;
    J = eta;

    eta_next = vartheta * psi_eta + zeta * (eye(size(A)) - omega * A * J) * (eta + eta_next) / 2;

    eta_diff = [eta_diff, abs(eta_next - eta)];

    % Check for convergence
    if eta_diff(end) < epsilon
        break;
    end

    eta = eta_next;
end

% Step 3: Calculate convergence rate and plot iterations = 1:iteration; convergence_rate = eta_diff(2:end) ./ eta_diff(1:end-1);

figure; subplot(2,1,1); plot(iterations, eta_diff); xlabel('Number of Iterations'); ylabel('|\eta_{n+1} - \eta_n|'); title('Convergence Rate');

subplot(2,1,2); plot(iterations(2:end), convergence_rate); xlabel('Number of Iterations'); ylabel('Convergence Rate'); title('Convergence Rate');

% Print the number of iterations until convergence fprintf('Convergence achieved in %d iterations.\n', iteration); ```