function?[weight?meanvec?stdvec]?=?EmEstimate（x?iternum）
%?x?is?the?input?observation?D-dim?vectors?*?N
%?iternum?is?the?given?number?for?EM?iterations
%?clear?all
%?dimension?of?each?data?point
%?load?gmm3data.mat
%?x?=?aaData;
D?=?size（x1）;
%?number?of?data?points
N?=?size（x2）;
%?fix?cluster?number
K?=?3;

%?calculate?the?global?mean?and?std?of?the?data
mean_global?=?mean（x?2）‘;??????%1*2
std_global?=?std（x?1?2）‘;?????%1*2

%?initialize?from?mean_global?std_global
weight?=?[1/3?1/3?1/3];
meanvec?=?zeros（K?D）;
meanvec（1?:）?=?mean_global?-?std_global;
meanvec（2?:）?=?mean_global;
meanvec（3?:）?=?mean_global?+?std_global;
stdvec?=?repmat（std_global?K?1）;

for?step?=?1:iternum???%i
????%%?E-step
????for?k?=?1:K
????????DATA?=?x‘-repmat（meanvec（k:）N1）;
????????pdf?=?DATA.^2./（repmat（stdvec（k:）N1））.^2;
????????pdf?=?exp（-0.5*sum（pdf2））/（2*pi*stdvec（k1）*stdvec（k2））;
????????gama_pdf（:k）?=?weight（k）*pdf;??%N*3
????end
????P?=?（gama_pdf./repmat（sum（gama_pdf2）1K））‘;????%3*N??
????%%?M-step
????for?i?=?1:D
????????for?k?=?1:K
????????????meanvec（ki）?=?sum（P（k:）.*x（i:））/sum（P（k:））;
????????????stdvec（ki）?=?sqrt（sum（P（k:）.*（x（i:）-meanvec（ki））.^2）/sum（P（k:）））;
????????????weight（k）?=?sum（P（k:））/?N;??
????????end
????end
end
end

?屬性????????????大小?????日期????時間???名稱
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?????文件????????412??2011-11-03?15:42??em\em.mat

?????文件???????1317??2011-11-03?15:44??em\EmEstimate.m

?????文件??????84480??2011-11-28?22:58??em\em.doc

?????目錄??????????0??2011-11-28?22:57??em

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????????????????86209????????????????????4