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  Categorizer::Learner::SVM, scores of categories?         

Author: Jiuan-Ru Jennifer Lai
Date: Mar 18, 2008 11:53


I used the Categorizer::SVM library for large data classification (great
tool); however, I'm having trouble analyzing the result from the SVM

- Categories have scores of either 0 or 1, with 1 being that this document
belongs to this category, and 0 otherwise. Are there any scores representing
probabilities or confidence level of belong to certain category other than
these 0, 1 values?
- Suppose this document could belong to 3 possible categories: cat1, cat2,
and cat3. The best_category method simply picks the first category as the
classification decision. If you call, $hypothesis->categories, the
categories outputed don't seem to be in the order of probabilities or
confidence level. They seem to be in the fixed order....and whatever listed
first is favored.

I hope someone can clear my confusion on the scores of categories in the
SVM module.

Thank you very much in advance,
no comments
  yawn cornerstone         

Author: Hester Newton
Date: Jul 15, 2007 07:57

Big News For SZSN! Shares Rocket! UP 37.5%%

Shandong Zhouyuan Seed and Nursery Co., Ltd (SZSN)
$0.33 UP 37.5%%

SZSN new releases show huge expansion and Multi-Million dollar projects.
Share prices rocket! Friday's trading was strong. Get On SZSN first
thing Monday!

Yes, it is that good. If they have work and family commitments, then
perhaps it is easier to set aside a weekend to see a large number of
bands in one go than go to regular gigs. He was detained by police in
Middlesex on Saturday in connection with failing to attend a court
hearing over alleged drugs offences in Glasgow.
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  Add documents to a learner?         

Author: Ignacio J. Ortega Lopera
Date: Jun 7, 2007 00:46

It's possible to add training to a learner? how?

What i try is to reopen a state file, and add new documents to the training
set without reading the entire corpus again..

It's seems that Algorithm::NativeBayes has a "purge" parameter that seems to
help doing that, it permit add new instances, after a train..

Saludios, Ignacio J. Ortega
no comments
  Re: Problems trying to predict         

Author: Ignacio J. Ortega Lopera
Date: Jun 7, 2007 00:41

Hola Ken:

Many thanks, your advice, did the trick.. nad yes it was when reloading
state from file..
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  AI::Categorizer suggestion for repackaging         

Author: Robert Barta
Date: Jun 4, 2007 09:27


This is probably more relevant to the maintainer of AI::Categorizer:

It would be a bit simpler to debianize the package if the dependency
to the Weka system would be factored out to a separate Perl package.

Otherwise I have not found a problem in making it a Debian package.

no comments
  AI::Categorizer and Umlauts?         

Author: Robert Barta
Date: Jun 4, 2007 09:08


I seem to have problems with umlauts, such as in words


When a document is added with

return new AI::Categorizer::Document(name => $filename,
content => $content);

to the collection, after loading and finish, the feature vector
contains only fragments of these words, such as

pr => 1
sentation => 1

Setting the locale on the shell or in Perl does not have any effect

use locale;

not even with turning on de_AT explicitly.


Aaaaaah, lib/AI/Categorizer/ is NOT using locale and use locale
is very, uhm, local %%-)

Patching the file does not seem to break the test cases.

no comments
  Problems trying to predict         

Author: Ignacio J. Ortega Lopera
Date: May 30, 2007 11:47

i'm getting this:

Can't locate object method "predict" via package
Frequency" at
m line 28.

when trying to get hypoteses.. for a new doc....

anyone know if this is a silly one?

Thanks in advance

Saludos, Ignacio J. Ortega
Technical manager
1 Comment
  package AI::Categorizer::Collection::DBI;         

Author: Ignacio J. Ortega Lopera
Date: May 30, 2007 09:48

Hola a todos:

When trying to use i've found that DBI try to read categories from database,
it trie to read a second column that seems to contain categories, it uses
something like [$result[1]].., my perl knowledge is a little poor to say the
least.. but it seems to my that code later expects this parameter as an
array of Category objects..

I've done a little change that permits that this second column be a list of
categories separated by commas, code ( can be a diff -u if needed)
attached, maybe it's usefull to anyone..

Thanks for that package, Ken, it's ... wonderful :)..

Saludos, Ignacio J. Ortega
Technical Manager
no comments
  how to use the function of "feature selection" under AI::Categorizer         

Author: Jhoon
Date: May 25, 2007 02:58


I’d like to select more important features using AI::Categorizer, and so
modified as follows
=== FROM ===
my $k = AI::Categorizer::KnowledgeSet->new( verbose => 1 );
=== TO ===
my $k = AI::Categorizer::KnowledgeSet->new( verbose => 1,
feature_selector => new AI::Categorizer::FeatureSelector::DocFrequency(
  verbose => 1,
  features_kept => 1000
=== END ===
I observed the performance according to change the value of features_kept,
but the performance is always same. I’d appreciate it if you tell me how
to do the feature selection using AI::Categorizer?

Thank you very much in advance.

no comments
  how to do feature selection         

Author: Jianmin WU
Date: May 19, 2007 05:42

hi, buddies,

I am not sure if i am in the right place. :-)

I am a fresh man to the perl and perl AI module.

I am trying to do the NaiveBayes experiments with the help of code in
example of the module of AI::Categorizer.
Now I am confused about how to do the feature selection.

The documents say that KnowledgeSet::load( ) will do feature selection and
read the corpus at the same time. So, I change the construction of
KnowledgeSet in from
my $k = AI::Categorizer::KnowledgeSet->new( verbose => 1 );
$k->load( collection => $training )
my $k = AI::Categorizer::KnowledgeSet->new( verbose => 1 , features_kept =
5000 );
$k->load( collection => $training )
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