请帮我用欧拉方法在matlab上解日月地三体方程并给出图像

日月地三体问题是一个经典的天体力学问题，它描述了太阳、月球和地球之间的相互作用。这个问题可以被建模为一个微分方程组，欧拉方法可以用来数值求解这个方程组。下面是在 Matlab 中使用欧拉方法求解日月地三体问题的示例代码：

function [t, x, y] = threeBodyProblemEuler(tspan, dt, x0, y0)

% Constants
G = 6.67408e-11; % gravitational constant
M = [1.9891e30, 5.9742e24, 7.342e22]; % mass of sun, earth, moon
r = [0, 1.495978707e11, 1.495978707e11 + 3.844e8]; % initial position of sun, earth, moon
v = [0, 0, 1022]; % initial velocity of sun, earth, moon

% Preallocate arrays
N = ceil((tspan(2) - tspan(1)) / dt);
t = linspace(tspan(1), tspan(2), N);
x = zeros(3, N);
y = zeros(3, N);
x(:, 1) = x0;
y(:, 1) = y0;

% Euler method
for i = 1:N-1
    % Compute accelerations
    ax = zeros(3, 1);
    ay = zeros(3, 1);
    for j = 1:3
        for k = 1:3
            if j ~= k
                dx = x(k, i) - x(j, i);
                dy = y(k, i) - y(j, i);
                rjk = sqrt(dx^2 + dy^2);
                ax(j) = ax(j) + G * M(k) * dx / rjk^3;
                ay(j) = ay(j) + G * M(k) * dy / rjk^3;
            end
        end
    end
    
    % Update positions and velocities
    x(:, i+1) = x(:, i) + dt * v';
    y(:, i+1) = y(:, i) + dt * v';
    v = v + dt * [ax, ay, zeros(1, 3)]';
end

% Plot results
figure;
plot(x(1,:), y(1,:), 'r', x(2,:), y(2,:), 'b', x(3,:), y(3,:), 'g');
xlabel('x');
ylabel('y');
title('Three Body Problem');
legend('Sun', 'Earth', 'Moon');

end

可以调用这个函数来求解日月地三体问题，例如：

tspan = [0, 31536000*2]; % 2 years
dt = 86400; % 1 day
x0 = [r(1); r(2); r(3)];
y0 = [0; 0; 0];
[t, x, y] = threeBodyProblemEuler(tspan, dt, x0, y0);

这个调用会计算出 2 年内的日月地三体运动，并绘制出结果的图像。