问matlab报错说hist必须是数值怎么解决？

代码如下

% Parameters for distributions

mu_X = 0; sigma_X = 1;

mu_Y = 5; sigma_Y = sqrt(5);

% Generate 1000 samples from X and Y

X = normrnd(mu_X, sigma_X, [1000, 1]);

Y = normrnd(mu_Y, sigma_Y, [1000, 1]);

% Generate Z = X + Y

Z = X + Y;

% Plot histograms

figure;

subplot(3,1,1);

hist(X, 'Normalization', 'pdf');

title('Histogram of X');

xlabel('X');

ylabel('Density');

subplot(3,1,2);

hist(Y, 'Normalization', 'pdf');

title('Histogram of Y');

xlabel('Y');

ylabel('Density');

subplot(3,1,3);

hist(Z, 'Normalization', 'pdf');

title('Histogram of Z');

xlabel('Z');

ylabel('Density');