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

Constructor Summary
C45Loader()
           
 
Method Summary
 Instances getDataSet()
          Return the full data set.
 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
static void main(java.lang.String[] args)
          Main method for testing this class.
 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
setSource
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

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

main

public static void main(java.lang.String[] args)
Main method for testing this class.

Parameters:
args - should contain [.names | data]


Copyright (c) 2003 David Lindsay, Computer Learning Research Centre, Dept. Computer Science, Royal Holloway, University of London