clc; close all; clear; % 多维联合高斯概率分布 %% % 二维联合概率分布 %方法一:调包 mu = zeros(1,2); % 均值 sigma = [1 , 0.9; 0.9 , 1]; % 协方差 rng('default') % For reproducibility X = mvnrnd(mu,sigma,1000); y = mvnpdf(X,mu,sigma); figure scatter3(X(:,1),X(:,2),y, '.') xlabel('X1') ylabel('X2') zlabel('Probability Density') %% %方法二:直接上公式 sigma2 = cov(X); mu2 = mean(X); y2 = sqrt(1/((2*pi)^length(mu2)*det(sigma2))) * exp(-1/2*(X-mu2)*inv(sigma2)*(X-mu2)'); y3 = zeros(1000, 1); for i = 1: 1000 y3(i) = y2(i, i); end figure scatter3(X(:,1),X(:,2),y3, '.') xlabel('X1') ylabel('X2') zlabel('Probability Density')
MATLAB不配拥有代码段格式吗。。。。。