s-function中的状态变量是一个元胞数组时，举一个全套的实例

好的，以下是一个简单的 S-Function，其中状态变量是一个包含两个元素的元胞数组：

function [sys,x0,str,ts] = my_sfun(t,x,u,flag)
% Define the number of states in the state vector
n_states = 2;

switch flag
    case 0 % Initialization
        % Set up the initial state vector as a cell array
        x0 = {zeros(n_states,1), ones(n_states,1)};
        % Set up the system sizes
        sizes = simsizes;
        sizes.NumContStates  = 0;
        sizes.NumDiscStates  = n_states;
        sizes.NumOutputs     = 1;
        sizes.NumInputs      = 1;
        sizes.DirFeedthrough = 0;
        sizes.NumSampleTimes = 1;
        % Return the system sizes
        sys = simsizes(sizes);
        % Initialize the state vector
        str = [];
        % Set the sample time
        ts = [0 0];
    case 1 % Calculation of derivatives (not applicable in this case)
        sys = [];
    case 2 % Update the discrete states
        % Get the previous state
        prev_state = x(1);
        % Get the input value
        input = u(1);
        % Calculate the new state
        new_state = prev_state + input;
        % Update the state vector
        x(1) = {new_state};
        % Calculate the output
        output = new_state;
        % Return the output and updated state vector
        sys = {output, x};
    case 3 % Calculation of outputs
        % Get the current state
        current_state = x(1);
        % Calculate the output
        output = current_state;
        % Return the output
        sys = output;
    case 4 % Termination (not used in this case)
        sys = [];
end

在本例中，状态变量是一个包含两个元素的元胞数组。在初始化阶段，我们使用以下代码将状态变量设置为一个包含两个元素的元胞数组：

x0 = {zeros(n_states,1), ones(n_states,1)};

在更新状态时，我们使用以下代码来获取先前的状态和输入值，并计算新状态：

prev_state = x(1);
input = u(1);
new_state = prev_state + input;

然后，我们使用以下代码来更新状态变量：

x(1) = {new_state};

在计算输出时，我们使用以下代码来获取当前状态并计算输出：

current_state = x(1);
output = current_state;

最后，我们使用以下代码返回输出：

sys = output;