AI::Categorizer::Learner::SVM - Support Vector Machine Learner

  use AI::Categorizer::Learner::SVM;

  # Here $k is an AI::Categorizer::KnowledgeSet object

  my $l = new AI::Categorizer::Learner::SVM(...parameters...);
  $l->train(knowledge_set => $k);
  $l->save_state('filename');

  ... time passes ...

  $l = AI::Categorizer::Learner->restore_state('filename');
  while (my $document = ... ) {  # An AI::Categorizer::Document object
    my $hypothesis = $l->categorize($document);
    print "Best assigned category: ", $hypothesis->best_category, "\n";
  }

This class implements a Support Vector Machine machine learner, using Cory Spencer's Algorithm::SVM module. In lots of the recent academic literature, SVMs perform very well for text categorization.

This class inherits from the AI::Categorizer::Learner class, so all of its methods are available unless explicitly mentioned here.

Creates a new SVM Learner and returns it. In addition to the parameters accepted by the AI::Categorizer::Learner class, the SVM subclass accepts the following parameters:

svm_kernel

Specifies what type of kernel should be used when building the SVM. Default is 'linear'. Possible values are 'linear', 'polynomial', 'radial' and 'sigmoid'.

Trains the categorizer. This prepares it for later use in categorizing documents. The knowledge_set parameter must provide an object of the class AI::Categorizer::KnowledgeSet (or a subclass thereof), populated with lots of documents and categories. See AI::Categorizer::KnowledgeSet for the details of how to create such an object.

Returns an AI::Categorizer::Hypothesis object representing the categorizer's "best guess" about which categories the given document should be assigned to. See AI::Categorizer::Hypothesis for more details on how to use this object.

Saves the categorizer for later use. This method is inherited from AI::Categorizer::Storable.

Ken Williams, ken@mathforum.org

Copyright 2000-2003 Ken Williams. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

AI::Categorizer(3), Algorithm::SVM(3)