uk.ac.ed.inf.csb.taweka
Class DataSetFactory

java.lang.Object
  uk.ac.ed.inf.csb.taweka.DataSetFactory

public class DataSetFactory
extends java.lang.Object

DataSet generates a collection of Weka instances (rows of the ARFF file), their attributes (column names) and their attribute values (cell values) The last attribute is the class attribute.

Version:

20 Feb 2008

Author:

Luna De Ferrari luna.deferrari-at-ed.ac.uk

Field Summary

static java.lang.String

DUMMY_VALUE

Constructor Summary

DataSetFactory(java.lang.String dataSetName, java.lang.String className, uk.ac.ed.inf.csb.utils.OneToManyMap instanceAttributeMap, uk.ac.ed.inf.csb.utils.OneToManyMap instanceClassMap)
Constructor for a data set.

Method Summary

weka.core.Attribute	generateClassAttribute() Generates the class attribute.
weka.core.Instances	generateDataSet() Create a set of instances and fill them with data
java.lang.String	getArffFormatString()
weka.core.Attribute	getAttributeByName(java.lang.String name)
weka.core.FastVector	getAttributes()
weka.core.Attribute	getClassAttribute()
weka.core.Instances	getDataSet()
java.lang.String	getDataSetName()
uk.ac.ed.inf.csb.utils.OneToManyMap	getInstanceAttributeData()
uk.ac.ed.inf.csb.utils.OneToManyMap	getInstanceClassData()
java.lang.String	getLog()
boolean	isLogged()
void	setDebug(boolean doLogErrors)

Methods inherited from class java.lang.Object

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

Field Detail

DUMMY_VALUE

public static final java.lang.String DUMMY_VALUE

See Also:

Constant Field Values

Constructor Detail

DataSetFactory

public DataSetFactory(java.lang.String dataSetName,
                      java.lang.String className,
                      uk.ac.ed.inf.csb.utils.OneToManyMap instanceAttributeMap,
                      uk.ac.ed.inf.csb.utils.OneToManyMap instanceClassMap)

Constructor for a data set. It can be visualised as: instances (rows), attributes (columns), class (last column), values (cells)

Parameters:

dataSetName - the data relation name

className - the class/category of the instance

instanceAttributeMap - TODO

instanceClassMap - TODO

Method Detail

generateDataSet

public weka.core.Instances generateDataSet()

Create a set of instances and fill them with data

Returns:

the data set

generateClassAttribute

public weka.core.Attribute generateClassAttribute()

Generates the class attribute. Adds a dummy start value (to work around a known weka bug described at http://weka.wikispaces.com/ARFF+%28stable+version%29) or http://www.cs.waikato.ac.nz/~ml/weka/arff.html) From Weka documentation: "Warning: There is a known problem saving SparseInstance objects from datasets that have string attributes. In Weka, string and nominal data values are stored as numbers; these numbers act as indexes into an array of possible attribute values (this is very efficient). However, the first string value is assigned index 0: this means that, internally, this value is stored as a 0. When a SparseInstance is written, string instances with internal value 0 are not output, so their string value is lost (and when the arff file is read again, the default value 0 is the index of a different string value, so the attribute value appears to change). To get around this problem, add a dummy string value at index 0 that is never used whenever you declare string attributes that are likely to be used in SparseInstance objects and saved as Sparse ARFF files."

Returns:

the class attribute

getArffFormatString

public java.lang.String getArffFormatString()

getDataSetName

public java.lang.String getDataSetName()

getAttributes

public weka.core.FastVector getAttributes()

getAttributeByName

public weka.core.Attribute getAttributeByName(java.lang.String name)

getInstanceAttributeData

public uk.ac.ed.inf.csb.utils.OneToManyMap getInstanceAttributeData()

getClassAttribute

public weka.core.Attribute getClassAttribute()

getDataSet

public weka.core.Instances getDataSet()

getInstanceClassData

public uk.ac.ed.inf.csb.utils.OneToManyMap getInstanceClassData()

isLogged

public boolean isLogged()

setDebug

public void setDebug(boolean doLogErrors)

getLog

public java.lang.String getLog()