[gensim:11757] What is the "topic diff" and what does it mean if "topic diff=inf"

[Johann Petrak]

Could somebody explain what exactly the "topic diff" value represents that
is shown on the log, apparently after every time a chunk is getting merged
into the model?

And what does it mean when the topic diff is shown to be "inf"?

If I keep getting a topic diff=inf are there specific steps that can be
taken to maybe improve the result? What I mean is: if this is an indication
of
a specific problem, is it possible to suggest specific informed steps like
e.g. increasing the number of topics or reducing alpha, rather than just
blindly trying everything?

Many thanks,

J.

[Johann Petrak]

Forgot to mention: this is in the context of training an LDA model using
LdaMulticore, in this concrete case, I used
num_topics=200, workers=12, passes=10, eval_every=5, random_state=100,
chunksize=10000, per_word_topics=True,minimum_probability=0
and everything else is left at the default values.
Gensim version is 3.4.0, if any of this matters.

Post by Johann Petrak
Could somebody explain what exactly the "topic diff" value represents that
is shown on the log, apparently after every time a chunk is getting merged
into the model?
And what does it mean when the topic diff is shown to be "inf"?
If I keep getting a topic diff=inf are there specific steps that can be
taken to maybe improve the result? What I mean is: if this is an indication
of
a specific problem, is it possible to suggest specific informed steps like
e.g. increasing the number of topics or reducing alpha, rather than just
blindly trying everything?
Many thanks,
J.