Maximum Likelihood Estimation function
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syms a
logL=100.*log(a)+sum(log(exp(a.*c2))+sum(log((1+exp(a.*c2)).^-2)));
j = fplot(logL)
hold on
%%
m=100/a;
o=sum(c);
p=2*exp(a.*c);
q=exp(a.*c)+1;
dlog=m+o-p.*c.*(q.^-1);
k=fplot(dlog);
hline.Color = 'k';
c is a matrix of data
I am trying to find the maximum of the estimator is there another method except plotting the graphs of the log functions?
采纳的回答
Torsten
2022-5-12
x = your data vector
fun = @(a) n/a + sum(x) - 2*a*sum(exp(a*x)./(exp(a*x)+1);
a = fzero(fun,1)
3 个评论
Jane Smith
2022-5-12
I think there is an error in your derivative of L with respect to a. In my opinion, the function must be
fun = @(a) n/a + sum(x) - 2*sum(x.*exp(a*x)./(exp(a*x)+1))
Jane Smith
2022-5-13
编辑：Jane Smith
2022-5-13
更多回答（1 个）
John D'Errico
2022-5-12
0 个投票
Is there another way? Why not negate the function, and then use a tool like fminbnd? Or fminsearch. Or fmincon or fminunc, or ...
2 个评论
Jane Smith
2022-5-12
I am getting errors when trying with those functions.
Error using fcnchk
FUN must be a function, a valid character vector expression, or an inline function object.
I have been trying it on various softwares. The function f(x) is made up so i am getting confused were my mistake is in finding the estimate.
David Randolph
2022-5-13
编辑：David Randolph
2022-5-13
@John D'Errico wrong again!
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