milk.core
Class Exemplar

java.lang.Object
  |
  +--milk.core.Exemplar

All Implemented Interfaces:

java.io.Serializable

public class Exemplar

extends java.lang.Object

implements java.io.Serializable

Class for handling an ordered set of weighted exemplars.

This class is not intended for reading directly from the Reader. Instead, the data should be pre-processed and then are tried to form an exemplar. The following members are still useful from the Instances class in the context of exemplar by using getInstances()
attribute(int)
attribute(String)
attributeStats(int)
attributeToDoubleArray(int)
checkForStringAttributes()
checkInstance(Instance)
classAttribute()
classIndex()
compactify()
delete()
delete(int)
deleteWithMissing(Attribute)
deleteWithMissing(int)
enumerateInstances()
firstInstance()
instance(int)
lastInstance()
meanOrMode(Attribute)
meanOrMode(int)
numAttributes()
numClasses()
numDistinctValues(Attribute)
numDistinctValues(int)
numInstances()
randomize(Random)
renameAttribute(Attribute, String)
renameAttribute(int, String)
renameAttributeValue(Attribute, String, String)
renameAttributeValue(int, int, String)
resample(Random)
resampleWithWeights(Random)
resampleWithWeights(Random, double[])
sort(Attribute)
sort(int)
stringFreeStructure()
sumOfWeights()
variance(Attribute)
variance(int) Typical usage is to read the instances from the Reader and try to feed it into into an array of Exemplars according to it's ID values

See Also:

Serialized Form

Constructor Summary

Exemplar(Exemplar exemplar)
Constructor to form an exemplar by copying from another exemplar

Exemplar(Exemplar exemplar, int size)
Constructor creating an empty Exemplar with the same structure of the given exemplar and the given size

Exemplar(weka.core.Instance inst, int id)
Constructor using one instance to form an exemplar

Exemplar(weka.core.Instances dataset)
Constructor copying all instances and references to the header information from the given set of instances.

Exemplar(weka.core.Instances dataset, int id)
Constructor creating an exemplar with the given dataset and the given ID index

Method Summary

void	add(weka.core.Instance instance) Adds one instance to the end of the set.
boolean	checkInstance(weka.core.Instance instance) Checks if the given instance is compatible with this Exemplar.
weka.core.Attribute	classAttribute() Returns the class attribute.
int	classIndex() Returns the class attribute's index.
double	classValue() Returns the class value of this exemplar.
void	compactify() Compactifies the set of instances in this exemplar
void	deleteAttributeAt(int position) Deletes an attribute at the given position (0 to numAttributes() - 1).
java.util.Enumeration	enumerateAttributes() Returns an enumeration of all the attributes.
weka.core.Instances	getInstances() Returns the dataset in this exemplar
weka.core.Attribute	idAttribute() Returns the ID attribute.
int	idIndex() Returns the ID attribute's index.
double	idValue() Returns the ID attribute's value.
void	insertAttributeAt(weka.core.Attribute att, int position) Inserts an attribute at the given position (0 to numAttributes()) and sets all values to be missing.
boolean	isAllMissing(int attIndex) Check whether the values of the specified attribute in this exemplar are all missing values
static void	main(java.lang.String[] args) Main method for testing this class -- just prints out a set of Exemplars.
double[]	meanOrMode() Returns the mean (mode) for all attributes (except ID and class) as a floating-point value.
int	numIds() Returns the number of ID labels.
void	setClassValue(double cv) Sets the class value of the exemplar
void	setWeight(double weight) Sets the weight of the exemplar.
java.lang.String	toString() Returns the exemplar as a string.
double[]	variance() Computes the variances for all numeric attributes.
double	weight() Returns the exemplar's weight.

Methods inherited from class java.lang.Object

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

Constructor Detail

Exemplar

public Exemplar(weka.core.Instance inst,
                int id)

Constructor using one instance to form an exemplar

Parameters:

id - the ID index

Exemplar

public Exemplar(Exemplar exemplar,
                int size)

Constructor creating an empty Exemplar with the same structure of the given exemplar and the given size

Parameters:

exemplar - the given exemplar

size - the given size

Exemplar

public Exemplar(Exemplar exemplar)

Constructor to form an exemplar by copying from another exemplar

Parameters:

exemplar - the copied exemplar

Exemplar

public Exemplar(weka.core.Instances dataset)
         throws java.lang.Exception

Constructor copying all instances and references to the header information from the given set of instances. Set the attribute with first index as exemplar ID

Throws:

if - the exemplar cannot be built properly

java.lang.Exception

Exemplar

public Exemplar(weka.core.Instances dataset,
                int id)
         throws java.lang.Exception

Constructor creating an exemplar with the given dataset and the given ID index

Parameters:

id - the index of the ID of the exemplar

Method Detail

add

public final void add(weka.core.Instance instance)

Adds one instance to the end of the set. Shallow copies instance before it is added. Increases the size of the dataset if it is not large enough. Does not check if the instance is compatible with the dataset.

Parameters:

instance - the instance to be added

checkInstance

public final boolean checkInstance(weka.core.Instance instance)

Checks if the given instance is compatible with this Exemplar.

Returns:

true if the instance is compatible with the exemplar

classAttribute

public final weka.core.Attribute classAttribute()

Returns the class attribute.

Returns:

the class attribute

Throws:

weka.core.UnassignedClassException - if the class is not set

classIndex

public final int classIndex()

Returns the class attribute's index. Returns negative number if it's undefined.

Returns:

the class index as an integer

classValue

public final double classValue()

Returns the class value of this exemplar.

Returns:

the class value

Throws:

weka.core.UnassignedClassException - if the class is not set

setClassValue

public void setClassValue(double cv)

Sets the class value of the exemplar

Parameters:

cv - the new class value

compactify

public final void compactify()

Compactifies the set of instances in this exemplar

deleteAttributeAt

public void deleteAttributeAt(int position)
                       throws java.lang.IllegalArgumentException

Deletes an attribute at the given position (0 to numAttributes() - 1). A deep copy of the attribute information is performed before the attribute is deleted.

Throws:

java.lang.IllegalArgumentException - if the given index is out of range or the class attribute is being deleted

enumerateAttributes

public java.util.Enumeration enumerateAttributes()

Returns an enumeration of all the attributes.

Returns:

enumeration of all the attributes.

getInstances

public weka.core.Instances getInstances()

Returns the dataset in this exemplar

Returns:

all the instances in the exemplar

idAttribute

public final weka.core.Attribute idAttribute()

Returns the ID attribute.

Returns:

the ID attribute

idIndex

public final int idIndex()

Returns the ID attribute's index.

Returns:

the ID index as an integer

idValue

public final double idValue()

Returns the ID attribute's value.

Returns:

the ID value of this exemplar

insertAttributeAt

public void insertAttributeAt(weka.core.Attribute att,
                              int position)

Inserts an attribute at the given position (0 to numAttributes()) and sets all values to be missing. Shallow copies the attribute before it is inserted, and performs a deep copy of the existing attribute information.

Parameters:

att - the attribute to be inserted

Throws:

java.lang.IllegalArgumentException - if the given index is out of range

meanOrMode

public final double[] meanOrMode()

Returns the mean (mode) for all attributes (except ID and class) as a floating-point value. Returns 0 if the attribute is neither nominal nor numeric. If all values are missing it returns zero.

Returns:

the mean or the mode of all attributes

variance

public final double[] variance()

Computes the variances for all numeric attributes. For nominal attribute, the variance is set to -1

Returns:

the variances for all numeric attributes

numIds

public final int numIds()

Returns the number of ID labels.

Returns:

the number of ID labels.

setWeight

public final void setWeight(double weight)

Sets the weight of the exemplar.

Parameters:

weight - the weight

toString

public final java.lang.String toString()

Returns the exemplar as a string. Strings are quoted if they contain whitespace characters, or if they are a question mark.

Overrides:

toString in class java.lang.Object

Returns:

the exemplar as a string

weight

public final double weight()

Returns the exemplar's weight.

Returns:

the exemplar's weight as a double

isAllMissing

public final boolean isAllMissing(int attIndex)

Check whether the values of the specified attribute in this exemplar are all missing values

Parameters:

attIndex - the specified attribute index

Returns:

whether values are all missing

main

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

Main method for testing this class -- just prints out a set of Exemplars. Assume the ID index is 0.