weka.core.converters
Class C45Loader

java.lang.Object
  weka.core.converters.AbstractLoader
      weka.core.converters.C45Loader

All Implemented Interfaces:

BatchLoader, IncrementalLoader, Loader, java.io.Serializable

public class C45Loader

extends AbstractLoader

implements BatchLoader, IncrementalLoader

Reads C4.5 input files. Takes a filestem or filestem with .names or .data appended. Assumes that both .names and .data exist in the directory of the supplied filestem.

Version:

$Revision: 1.5 $

Author:

Mark Hall (mhall@cs.waikato.ac.nz)

See Also:

Loader, Serialized Form

Field Summary

private java.io.Reader	m_dataReader Reader for data file
private java.lang.String	m_fileStem Holds the filestem.
private boolean[]	m_ignore Which attributes are ignore or label.
private java.io.Reader	m_namesReader Reader for names file
private int	m_numAttribs Number of attributes in the data (including ignore and label attributes).
protected java.io.File	m_sourceFile Holds the source of the data set.
private java.io.File	m_sourceFileData Describe variable m_sourceFileData here.
protected Instances	m_structure Holds the determined structure (header) of the data set.

Fields inherited from class weka.core.converters.AbstractLoader

BATCH, INCREMENTAL, m_retrieval, NONE

Constructor Summary

C45Loader()

Method Summary

Instances	getDataSet() Return the full data set.
private Instance	getInstance(java.io.StreamTokenizer tokenizer) Reads an instance using the supplied tokenizer.
Instance	getNextInstance() Read the data set incrementally---get the next instance in the data set or returns null if there are no more instances to get.
Instances	getStructure() Determines and returns (if possible) the structure (internally the header) of the data set as an empty set of instances.
java.lang.String	globalInfo() Returns a string describing this attribute evaluator
private void	initTokenizer(java.io.StreamTokenizer tokenizer) Initializes the stream tokenizer
static void	main(java.lang.String[] args) Main method for testing this class.
private void	readHeader(java.io.StreamTokenizer tokenizer) Reads header (from the names file) using the supplied tokenizer
private java.lang.String	removeTrailingPeriod(java.lang.String val)
void	reset() Resets the Loader ready to read a new data set
void	setSource(java.io.File file) Resets the Loader object and sets the source of the data set to be the supplied File object.

Methods inherited from class weka.core.converters.AbstractLoader

getRetrieval, setRetrieval, setSource

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_structure

protected Instances m_structure

Holds the determined structure (header) of the data set.

m_sourceFile

protected java.io.File m_sourceFile

Holds the source of the data set. In this case the names file of the data set. m_sourceFileData is the data file.

m_sourceFileData

private java.io.File m_sourceFileData

Describe variable m_sourceFileData here.

m_namesReader

private transient java.io.Reader m_namesReader

Reader for names file

m_dataReader

private transient java.io.Reader m_dataReader

Reader for data file

m_fileStem

private java.lang.String m_fileStem

Holds the filestem.

m_numAttribs

private int m_numAttribs

Number of attributes in the data (including ignore and label attributes).

m_ignore

private boolean[] m_ignore

Which attributes are ignore or label. These are *not* included in the arff representation.

Constructor Detail

C45Loader

public C45Loader()

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this attribute evaluator

Returns:

a description of the evaluator suitable for displaying in the explorer/experimenter gui

reset

public void reset()

Resets the Loader ready to read a new data set

setSource

public void setSource(java.io.File file)
               throws java.io.IOException

Resets the Loader object and sets the source of the data set to be the supplied File object.

Specified by:

setSource in interface Loader

Overrides:

setSource in class AbstractLoader

Parameters:

file - the source file.

Throws:

java.io.IOException - if an error occurs

getStructure

public Instances getStructure()
                       throws java.io.IOException

Determines and returns (if possible) the structure (internally the header) of the data set as an empty set of instances.

Specified by:

getStructure in interface Loader

Specified by:

getStructure in class AbstractLoader

Returns:

the structure of the data set as an empty set of Instances

Throws:

java.io.IOException - if an error occurs

getDataSet

public Instances getDataSet()
                     throws java.io.IOException

Return the full data set. If the structure hasn't yet been determined by a call to getStructure then method should do so before processing the rest of the data set.

Specified by:

getDataSet in interface Loader

Specified by:

getDataSet in class AbstractLoader

Returns:

the structure of the data set as an empty set of Instances

Throws:

java.io.IOException - if there is no source or parsing fails

getNextInstance

public Instance getNextInstance()
                         throws java.io.IOException

Read the data set incrementally---get the next instance in the data set or returns null if there are no more instances to get. If the structure hasn't yet been determined by a call to getStructure then method should do so before returning the next instance in the data set. If it is not possible to read the data set incrementally (ie. in cases where the data set structure cannot be fully established before all instances have been seen) then an exception should be thrown.

Specified by:

getNextInstance in interface Loader

Specified by:

getNextInstance in class AbstractLoader

Returns:

the next instance in the data set as an Instance object or null if there are no more instances to be read

Throws:

java.io.IOException - if there is an error during parsing

getInstance

private Instance getInstance(java.io.StreamTokenizer tokenizer)
                      throws java.io.IOException

Reads an instance using the supplied tokenizer.

Parameters:

tokenizer - the tokenizer to use

Returns:

an Instance or null if there are no more instances to read

Throws:

java.io.IOException - if an error occurs

removeTrailingPeriod

private java.lang.String removeTrailingPeriod(java.lang.String val)

readHeader

private void readHeader(java.io.StreamTokenizer tokenizer)
                 throws java.io.IOException

Reads header (from the names file) using the supplied tokenizer

Parameters:

tokenizer - the tokenizer to use

Throws:

java.io.IOException - if an error occurs

initTokenizer

private void initTokenizer(java.io.StreamTokenizer tokenizer)

Initializes the stream tokenizer

Parameters:

tokenizer - the tokenizer to initialize

main

public static void main(java.lang.String[] args)

Main method for testing this class.

Parameters:

args - should contain [.names | data]