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final turnin

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This commit is contained in:
Michael Zhang 2023-10-08 12:48:13 -05:00
parent d79046d7b9
commit 3f2f1ef665
1 changed files with 9 additions and 9 deletions
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18
gauss_class/gauss_class_2D.m
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@ -17,8 +17,8 @@ mu1 = [-1 -1];
mu2 = [1 1];
% Equal diagnoal covariance matrix
Sigma1 = [1 0; 0 1];
Sigma2 = [1 0; 0 1];
% Sigma1 = [1 0; 0 1];
% Sigma2 = [1 0; 0 1];
% Diagnoal covariance matrix
% Sigma1 = [1 0; 0 0.5];
@ -31,22 +31,22 @@ mu2 = [1 1];
x1 = -10:.1:10; x2 = -10:.1:10;
% covariance matrix (increase the range for visualization)
% Sigma1 = [1 0.1; 0.1 0.5];
% Sigma2 = [0.5 0.3; 0.3 1];
% x1 = -40:.1:40; x2 = -40:.1:40;
Sigma1 = [1 0.1; 0.1 0.5];
Sigma2 = [0.5 0.3; 0.3 1];
x1 = -40:.1:40; x2 = -40:.1:40;
[X1,X2] = meshgrid(x1,x2);
%pdf1
% F1 = mvnpdf([X1(:) X2(:)],mu1,Sigma1);
F1 = mvndis([X1(:) X2(:)], mu1, Sigma1, prior1);
F1 = reshape(prior1 * F1,length(x2),length(x1));
F1 = reshape(F1,length(x2),length(x1));
subplot(1,2,1);
surf(x1,x2,F1); hold on;
%pdf2
% F2 = mvnpdf([X1(:) X2(:)],mu2,Sigma2);
F2 = mvndis([X1(:) X2(:)], mu2, Sigma2, prior2);
F2 = reshape(prior2 * F2,length(x2),length(x1));
F2 = reshape(F2,length(x2),length(x1));
surf(x1,x2,F2);
caxis([min(F2(:))-.5*range(F2(:)),max(F2(:))]);
axis([-4 4 -4 4 0 .4])
@ -66,13 +66,13 @@ xlabel('x1'); ylabel('x2');
function res = mvndis(X, mu, Sigma, prior)
[len, ~] = size(X);
[len, d] = size(X);
res = zeros(len, 1);
for i = 1:len
x = X(i,:);
mdist = (x - mu) * inv(Sigma) * (x - mu).';
res(i) = -log(2*pi) - 1/2*log(det(Sigma)) - 1/2*mdist + log(prior);
res(i) = -d/2*log(2*pi) - 1/2*log(det(Sigma)) - 1/2*mdist + log(prior);
end
% 1 x 2
% (1 x 2) x ((2 x 2) x (2 x 1))