weka.core.stats

Class NominalStats

java.lang.Object

weka.core.stats.Stats

weka.core.stats.NominalStats

All Implemented Interfaces:

java.io.Serializable

public class NominalStats
extends Stats
implements java.io.Serializable

Class for computing nominal statistics (primarily frequency counts)

Version:

$Revision: 10929 $

Author:

Mark Hall (mhall{[at]}pentaho{[dot]}com)

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NominalStats.Count Class that encapsulates a count for nominal value

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	MISSING_LABEL A "label" to use when storing the number of missing values

Constructor Summary

Constructors

Constructor and Description
NominalStats(java.lang.String attributeName) Constructs a new NominalStats

Method Summary

Modifier and Type	Method and Description
void	add(java.lang.String label, double value) Adds to the count for a given label.
static NominalStats	attributeToStats(weka.core.Attribute a) Convert a summary meta attribute to a NominalStats
double	getCount(java.lang.String label) Get the count for a given label
java.util.Set<java.lang.String>	getLabels() Get the set of labels seen by this NominalStats
int	getMode() Get the index of the mode
java.lang.String	getModeLabel() Get the most frequent label (not including missing values)
double	getNumMissing() Get the number of missing values for this attribute
weka.core.Attribute	makeAttribute() Makes a Attribute that encapsulates the meta data
void	setNumMissing(double missing) Set the number of missing values for this attribute

Methods inherited from class weka.core.stats.Stats

getName

Methods inherited from class java.lang.Object

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

Field Detail

MISSING_LABEL

public static final java.lang.String MISSING_LABEL

A "label" to use when storing the number of missing values

See Also:

Constant Field Values

Constructor Detail

NominalStats

public NominalStats(java.lang.String attributeName)

Constructs a new NominalStats

Parameters:

attributeName - the name of the data attribute that these stats pertain to

Method Detail

attributeToStats

public static NominalStats attributeToStats(weka.core.Attribute a)
                                     throws java.lang.IllegalArgumentException

Convert a summary meta attribute to a NominalStats

Parameters:

a - the attribute to convert

Returns:

a NominalStats

Throws:

java.lang.IllegalArgumentException - if a problem occurs

add

public void add(java.lang.String label,
                double value)

Adds to the count for a given label. If the label is null then it adds to the count for missing.

Parameters:

label - the label to add the count to

value - the count to add

getLabels

public java.util.Set<java.lang.String> getLabels()

Get the set of labels seen by this NominalStats

Returns:

the set of labels

getCount

public double getCount(java.lang.String label)

Get the count for a given label

Parameters:

label - the label to get the count for

Returns:

the count or missing value if the label is unknown

getNumMissing

public double getNumMissing()

Get the number of missing values for this attribute

Returns:

the number of missing values seen

getMode

public int getMode()

Get the index of the mode

Returns:

the index (in the sorted list of labels) of the mode

getModeLabel

public java.lang.String getModeLabel()

Get the most frequent label (not including missing values)

Returns:

the most frequent label

setNumMissing

public void setNumMissing(double missing)

Set the number of missing values for this attribute

Parameters:

missing - the number of missing values

makeAttribute

public weka.core.Attribute makeAttribute()

Description copied from class: Stats

Makes a Attribute that encapsulates the meta data

Specified by:

makeAttribute in class Stats

Returns:

an Attribute that encapsulates the meta data