MATLAB实例：二元高斯分布图
作者：凯鲁嘎吉 - 博客园 http://www.cnblogs.com/kailugaji/
1. MATLAB程序
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%% demo Multivariate Normal Distribution
clear
clc
%% 空间坐标范围
x1=-5:0.2:5;
x2=-5:0.2:5;
[X1, X2]=
meshgrid
(x1, x2);
X=[X1(:) X2(:)];
%% 高斯分布参数
% 分量1
miu_1=[1 1];
% 均值
Sigma_1=[2 -2;-2 3];
% 协方差
% 分量2
miu_2=[0 -2];
% 均值
Sigma_2=[5 0.5;0.5 1];
% 协方差
%% 高斯概率密度函数
% 分量1
y_1=mvnpdf(X, miu_1, Sigma_1);
y_1=
reshape
(y_1,
length
(x2),
length
(x1));
% 分量2
y_2=mvnpdf(X, miu_2, Sigma_2);
y_2=
reshape
(y_2,
length
(x2),
length
(x1));
%% 2D密度图
figure
(1);
contour
(x1, x2, y_1);
hold
on
contour
(x1, x2, y_2);
xlabel
(
'x1'
);
ylabel
(
'x2'
);
saveas
(
gcf
,
sprintf
(
'Gauss_2D.jpg'
),
'bmp'
);
%% 3D密度图
figure
(2);
surf
(x1, x2, y_1);
hold
on
surf
(x1, x2, y_2);
xlabel
(
'x1'
);
ylabel
(
'x2'
);
zlabel
(
'Probability Density'
);
saveas
(
gcf
,
sprintf
(
'Gauss_3D.jpg'
),
'bmp'
);
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2. 结果
