如何在三维曲面上绘制matlab梯度下降的推进图

[X, Y] = meshgrid(-10:0.5:10);
Z = X.^2 + Y.^2;

figure;
surf(X, Y, Z);

alpha = 0.1; % 学习率
num_iterations = 100; % 迭代次数

% 初始化起始点
start_x = -9;
start_y = 9;
current_x = start_x;
current_y = start_y;

% 迭代更新位置
for i = 1:num_iterations
    % 计算当前位置的梯度
    grad_x = 2 * current_x;
    grad_y = 2 * current_y;
    
    % 更新位置
    current_x = current_x - alpha * grad_x;
    current_y = current_y - alpha * grad_y;
    
    % 绘制当前位置
    hold on;
    plot3(current_x, current_y, current_x^2 + current_y^2, 'ro', 'MarkerSize', 5);
    drawnow;
end