matlab 中极大似然法mle错误求助
clc;clear;A=csvread('c:\wk.txt');
m=6;
n=floor(length(A)/m);
for i=1:n;
y(i)=max(A([(i-1)*m+1:(i*m)]));
end
%hist(y,15);
x=y;
mypdf=@(x,a,b,u)(exp(-(1+b.*(x-u)/a).^(-1/b))./b.*(-(1+b.*(x-u)/a).^(-1/b-1)));
mycdf=@(x,a,b,u)(exp(-(1+b.*(x-u)/a).^(-1/b)));
=mle(x,'pdf',mypdf,'cdf',mycdf,'start',[.1,.5,.1])
Error using mlecustom>llf_pdfcdf (line 440)
The PDF function returned negative or zero values.
Error in fminsearch (line 191)
fv(:,1) = funfcn(x,varargin{:});
Error in mlecustom (line 183)
= ...
Error in mle (line 229)
= mlecustom(data,varargin{:});
Error in Untitled2 (line 12)
=mle(x,'pdf',mypdf,'cdf',mycdf,'start',[.1,.5,.1])
这个和你的概率密度函数的定义有关，错误提示说这个函数返回了负值或者零值，这是不允许的，你好好推敲一下它的定义
Error using mlecustom>llf_pdfcdf (line 440)
The PDF function returned negative or zero values. 表情那里是 冒号和（
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