[Topic-models] Why is E step of LDA iterative

Yuanlong Shao shaoyuanlong at cad.zju.edu.cn
Sun Nov 23 01:50:02 EST 2008

Thank you. But I still don't understand, normally, when max f(x,y), we
compute partial derivatives

for each variables and set them to 0, we get an equation set and solve them,

but for this problem, since closed form solution does not exist, we are
iteratively updating them,

then how to ensure the convergence? I'm trying to figure whether I can apply
the same method

to similar problems. 


Best Regards,


Yuanlong Shao

State Key Lab of CAD&CG

Zhejiang University


From: Veena T [mailto:veenat2005 at gmail.com] 
Sent: 2008年11月23日 14:17
To: shaoyuanlong at cad.zju.edu.cn
Cc: topic-models at lists.cs.princeton.edu
Subject: Re: [Topic-models] Why is E step of LDA iterative


>Hi, all

>Why is the E step of LDA iterative? I mean the updating formula of \gamma
>and \phi.
Because there is interdependency between themselves

>In my algorithm, there are more variables to be updated in E step,

>is there any situation that such iterative E step does not converge or
>oscillate repeatedly?
I am not sure


Veena Srinivas,
PhD scholar,
Speech and Vision Lab
IIT Madras, Chennai-36
Tamil Nadu

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