## Package org.apache.mahout.classifier.bayes

The Bayes example package provides some helper classes for training the Naive Bayes classifier on the Twenty Newsgroups data.

See:
Description

Interface Summary
SplitBayesInput.SplitCallback: Used to pass information back to a caller once a file has been split without the need for a data object

Class Summary
PrepareTwentyNewsgroups: Prepare the 20 Newsgroups files for training using the `BayesFileFormatter`.
SplitBayesInput: A utility for splitting files in the input format used by the Bayes classifiers into training and test sets in order to perform cross-validation.
WikipediaDatasetCreatorDriver: Create and run the Wikipedia Dataset Creator.
WikipediaDatasetCreatorMapper: Maps over Wikipedia xml format and output all document having the category listed in the input category file
WikipediaDatasetCreatorOutputFormat: This class extends the MultipleOutputFormat, allowing to write the output data to different output files in sequence file output format.
WikipediaDatasetCreatorReducer: Can also be used as a local Combiner
WikipediaXmlSplitter: Splits the wikipedia xml file in to chunks of size as specified by command line parameter
XmlInputFormat: Reads records that are delimited by a specific begin/end tag.
XmlInputFormat.XmlRecordReader: XMLRecordReader class to read through a given xml document to output xml blocks as records as specified by the start tag and end tag

## Package org.apache.mahout.classifier.bayes Description

The Bayes example package provides some helper classes for training the Naive Bayes classifier on the Twenty Newsgroups data. See `PrepareTwentyNewsgroups` for details on running the trainer. See `PrepareTwentyNewsgroups` for details on formatting the Twenty Newsgroups data properly for the training.
The easiest way to prepare the data is to use the ant task in core/build.xml:

        ant extract-20news-18828

This runs the arg line:

        -p ${working.dir}/20news-18828/ -o ${working.dir}/20news-18828-collapse -a ${analyzer} -c UTF-8

To Run the Wikipedia examples (assumes you've built the Mahout Job jar):

1. Download the Wikipedia Dataset. Use the Ant target: ant enwiki-files
2. Chunk the data using the WikipediaXmlSplitter (from the Hadoop home):
   bin/hadoop jar <PATH TO MAHOUT>/target/mahout-examples-0.2 org.apache.mahout.classifier.bayes.WikipediaXmlSplitter -d <MAHOUT_HOME>/examples/temp/enwiki-latest-pages-articles.xml -o <MAHOUT_HOME>/examples/work/wikipedia/chunks/ -c 64

Copyright © 2008 Apache Software Foundation

Copyright © 2008-2010 The Apache Software Foundation. All Rights Reserved.