weka.core.converters

Class ArffLoader

java.lang.Object

weka.core.converters.AbstractLoader

weka.core.converters.AbstractFileLoader

weka.core.converters.ArffLoader

All Implemented Interfaces:

java.io.Serializable, BatchConverter, FileSourcedConverter, IncrementalConverter, Loader, URLSourcedLoader, EnvironmentHandler, RevisionHandler

public class ArffLoader
extends AbstractFileLoader
implements BatchConverter, IncrementalConverter, URLSourcedLoader

Reads a source that is in arff (attribute relation file format) format.

Version:

$Revision: 11137 $

Author:

Mark Hall (mhall@cs.waikato.ac.nz), FracPete (fracpete at waikato dot ac dot nz)

See Also:

Loader, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ArffLoader.ArffReader Reads data from an ARFF file, either in incremental or batch mode.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	FILE_EXTENSION the file extension
static java.lang.String	FILE_EXTENSION_COMPRESSED

Fields inherited from interface weka.core.converters.Loader

BATCH, INCREMENTAL, NONE

Constructor Summary

Constructors

Constructor and Description
ArffLoader()

Method Summary

Modifier and Type	Method and Description
Instances	getDataSet() Return the full data set.
java.lang.String	getFileDescription() Returns a description of the file type.
java.lang.String	getFileExtension() Get the file extension used for arff files
java.lang.String[]	getFileExtensions() Gets all the file extensions used for this type of file
Instance	getNextInstance(Instances structure) Read the data set incrementally---get the next instance in the data set or returns null if there are no more instances to get.
java.lang.String	getRevision() Returns the revision string.
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 Loader
static void	main(java.lang.String[] args) Main method.
void	reset() Resets the Loader ready to read a new data set or the same data set again.
java.io.File	retrieveFile() get the File specified as the source
java.lang.String	retrieveURL() Return the current url
void	setFile(java.io.File file) sets the source File
void	setSource(java.io.InputStream in) Resets the Loader object and sets the source of the data set to be the supplied InputStream.
void	setSource(java.net.URL url) Resets the Loader object and sets the source of the data set to be the supplied url.
void	setURL(java.lang.String url) Set the url to load from

Methods inherited from class weka.core.converters.AbstractFileLoader

getUseRelativePath, runFileLoader, setEnvironment, setSource, setUseRelativePath, useRelativePathTipText

Methods inherited from class weka.core.converters.AbstractLoader

setRetrieval

Methods inherited from class java.lang.Object

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

Field Detail

FILE_EXTENSION

public static java.lang.String FILE_EXTENSION

the file extension

FILE_EXTENSION_COMPRESSED

public static java.lang.String FILE_EXTENSION_COMPRESSED

Constructor Detail

ArffLoader

public ArffLoader()

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this Loader

Returns:

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

getFileExtension

public java.lang.String getFileExtension()

Get the file extension used for arff files

Specified by:

getFileExtension in interface FileSourcedConverter

Returns:

the file extension

getFileExtensions

public java.lang.String[] getFileExtensions()

Gets all the file extensions used for this type of file

Specified by:

getFileExtensions in interface FileSourcedConverter

Returns:

the file extensions

getFileDescription

public java.lang.String getFileDescription()

Returns a description of the file type.

Specified by:

getFileDescription in interface FileSourcedConverter

Returns:

a short file description

reset

public void reset()
           throws java.io.IOException

Resets the Loader ready to read a new data set or the same data set again.

Specified by:

reset in interface Loader

Overrides:

reset in class AbstractFileLoader

Throws:

java.io.IOException - if something goes wrong

setSource

public void setSource(java.net.URL url)
               throws java.io.IOException

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

Parameters:

url - the source url.

Throws:

java.io.IOException - if an error occurs

retrieveFile

public java.io.File retrieveFile()

get the File specified as the source

Specified by:

retrieveFile in interface FileSourcedConverter

Overrides:

retrieveFile in class AbstractFileLoader

Returns:

the source file

setFile

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

sets the source File

Specified by:

setFile in interface FileSourcedConverter

Overrides:

setFile in class AbstractFileLoader

Parameters:

file - the source file

Throws:

java.io.IOException - if an error occurs

setURL

public void setURL(java.lang.String url)
            throws java.io.IOException

Set the url to load from

Specified by:

setURL in interface URLSourcedLoader

Parameters:

url - the url to load from

Throws:

java.io.IOException - if the url can't be set.

retrieveURL

public java.lang.String retrieveURL()

Return the current url

Specified by:

retrieveURL in interface URLSourcedLoader

Returns:

the current url

setSource

public void setSource(java.io.InputStream in)
               throws java.io.IOException

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

Specified by:

setSource in interface Loader

Overrides:

setSource in class AbstractLoader

Parameters:

in - the source InputStream.

Throws:

java.io.IOException - always thrown.

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(Instances structure)
                         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.

Specified by:

getNextInstance in interface Loader

Specified by:

getNextInstance in class AbstractLoader

Parameters:

structure - the dataset header information, will get updated in case of string or relational attributes

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

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision

main

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

Main method.

Parameters:

args - should contain the name of an input file.