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Ask/Poll News.YC: What is a good open source Bayes classifier?

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Re: Ask/Poll News.YC: What is a good open source Bayes classifier?

#31

Post by fiaz »

food79 wrote: post #30
fiaz wrote: post #29

Earlier quoted context omitted.

Is there any documentation that stands out for learning the alien language? No doubt, I'll be combing through all of the CRM114 information on the website. Is there anything that is not referenced there that will be of use?

If you are doing a ham/spam type classification, then you won't need the alien language. I am almost a total tech novice and I was able to do well with just some bash scripts. Of course the docs will teach you about better ways to train the system, if you are interested in going from 98% correct classification to 99.5% correct. learn ham.css learn spam.css classify < file_to_classify.txt

I am NOT doing ham/spam type classification. I need to define some classifications for specific types of content.

Re: Ask/Poll News.YC: What is a good open source Bayes classifier?

#33

Post by apgwoz »

dreish wrote: post #18
jgrahamc wrote: post #6

Earlier quoted context omitted.

Sounds to me that you are describing Laplace Smoothing in a Naive Bayes classifier. This is a pretty standard technique for avoiding the problem that you are seeing where the probability comes out as 100%/0% because of a lack of information in the model.

Thanks, yes, that's what it's called. All due credit to Laplace for the technique, but the word "smoothing" is making me wince, because it makes it sound as though this is some artificial approximation. For the assumption of an even distribution of probabilities, n+1 / m+2 really _is_ the exact probability of the event repeating. Like I said, you can confirm this experimentally with a quick program.

There are other smoothing techniques more prevalent in NLP that I'm learning about in my NLP class which distribute probability mass more evenly, but really won't help (at least I don't think so) in a classifier. Witten-Bell and Good-Turing are the ones I can think of off the top of my head.

Re: Ask/Poll News.YC: What is a good open source Bayes classifier?

#36

Post by jorgeortiz85 »

fiaz wrote: post #32
yawl wrote: post #19

I use Weka in my project. Btw, there is a book about Weka: http://www.cs.waikato.ac.nz/~ml/weka/book.html

How does Weka differ from CRM114?

I'm not familiar with CRM114, but upon cursory inspection it seems to be written in C and targeted mainly at document classification.

Weka is written in Java and implements all kinds of machine learning/data mining tools.

Re: Ask/Poll News.YC: What is a good open source Bayes classifier?

#37

Post by fiaz »

pg wrote: post #20

crm114

pg has spoken, and it is good...

Seriously though this is exactly what I need to accomplish my tasks (which is not SPAM filtering). I briefly looked at all of the other alternatives before diving deeper into the "CRM114 Revealed" book. I really wish I knew about this a few years earlier!!

Re: Ask/Poll News.YC: What is a good open source Bayes classifier?

#38

Post by a-priori »

fiaz wrote: post #31
food79 wrote: post #30

Earlier quoted context omitted.

If you are doing a ham/spam type classification, then you won't need the alien language. I am almost a total tech novice and I was able to do well with just some bash scripts. Of course the docs will teach you about better ways to train the system, if you are interested in going from 98% correct classification to 99.5% correct. learn ham.css learn spam.css classify < file_to_classify.txt

I am NOT doing ham/spam type classification. I need to define some classifications for specific types of content.

Then substitute ham/spam for whatever those types of content are.
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