edu.udo.cs.yale.example
Class NominalAttribute

java.lang.Object
  edu.udo.cs.yale.example.AbstractAttribute
      edu.udo.cs.yale.example.NominalAttribute

All Implemented Interfaces:

Attribute, java.lang.Cloneable

public class NominalAttribute
extends AbstractAttribute

This class holds all information on a single nominal attribute. In addition to the generic attribute fields this class keeps information about the nominal values and the value to index mappings. If one of the methods designed for numerical attributes was invoked a RuntimeException will be thrown. It will be guaranteed that all values are mapped to indices without any missing values.

Version:

$Id: NominalAttribute.java,v 2.12 2006/04/05 08:57:22 ingomierswa Exp $

Author:

Ingo Mierswa

Field Summary

private int[]	indexToCounterMap A map between symbolic values and a counter how often the value occurs in the data.
private java.util.List<java.lang.String>	indexToSymbolMap The map between indices of nominal values and the actual nominal value.
private static int	MAX_NUMBER_OF_SHOWN_NOMINAL_VALUES The maximum number of nominal values displayed in result strings.
private java.lang.String	mode The mode value for this attribute.
private java.util.Map<java.lang.String,java.lang.Integer>	symbolToIndexMap The map between symbolic values and their indices.

Fields inherited from class edu.udo.cs.yale.example.AbstractAttribute

HIGHEST_BLOCK_NUMBER

Fields inherited from interface edu.udo.cs.yale.example.Attribute

UNDEFINED_ATTRIBUTE_INDEX, UNDEFINED_BLOCK_NUMBER, UNIT_NAMES

Constructor Summary

protected	NominalAttribute(java.lang.String name) Creates a simple attribute which is not part of a series and does not provide a unit string.
protected	NominalAttribute(java.lang.String name, int valueType) Creates a simple attribute which is not part of a series and does not provide a unit string.

Method Summary

void	clearMaps() Clears all mappings for nominal values.
java.lang.Object	clone() Clones this attribute.
void	copyProperties(Attribute attribute) Copies all properties from the given attribute.
private void	ensureClassification() Throws a runtime exception if this attribute is not a classification attribute.
java.lang.String	getAsString(double value, int digits) Returns a string representation and maps value to a string if type is nominal.
double	getAverage() Not supported for nominal attributes.
int	getIndex(java.lang.String str) Returns the index of the given nominal value or -1 if this value was not mapped before by invoking the method mapIndex(int).
double	getMaximum() Not supported for nominal attributes.
double	getMinimum() Not supported for nominal attributes.
java.lang.String	getMode() Returns the mode for this attribute.
int	getNegativeIndex() Returns the index of the first value if this attribute is a classification attribute, i.e. if it is binominal.
int	getNumberOfValues() Returns the number of different nominal values.
int	getPositiveIndex() Returns the index of the second value if this attribute is a classification attribute.
java.lang.String	getStatisticsString() Returns a string representation of the range (numerical attribute) or class values (nominal attribute).
int	getValueCount(java.lang.String value) Returns the number of occurences of the given nominal value.
java.util.Collection<java.lang.String>	getValues() Returns the values of the attribute as an enumeration of strings.
double	getVariance() Not supported for nominal attributes.
boolean	isBooleanClassification() Returns true if this attribute is nominal attribute with two different class values.
boolean	isDefault(double value) Returns true iff value is the default value for this attribute.
boolean	isNominal() Returns true if this attribute is nominal.
boolean	isNumerical() Returns true if this attribute is nominal.
java.lang.String	mapIndex(int index) Returns the attribute value, that is associated with this index.
int	mapString(java.lang.String str) Returns the index for the nominal attribute value str.
void	readAttributeData(java.io.DataInput in) Overrides the super method and reads information about the nominal values.
void	replaceValue(java.lang.String oldValue, java.lang.String newValue) Replaces the old value with the new one.
void	setAverage(double a) Not supported for nominal attributes.
void	setIndexToCounterMap(int[] indexToCounterMap) Sets the index to counter map, e.g. after recalculating the attribute statistics.
void	setMaximum(double v) Not supported for nominal attributes.
void	setMinimum(double v) Not supported for nominal attributes.
void	setMode(java.lang.String mode) Sets the mode for this attribute.
void	setVariance(double v) Not supported for nominal attributes.
void	sortNominalMappings() This method rearranges the string to number mappings such that they are in alphabetical order.
private void	throwNonNumericalException(java.lang.String message) Throws a runtime exception.
java.lang.String	toString() Returns a human readable string that describes this attribute.
void	writeAttributeData(java.io.DataOutput out) Overrides the super method and add information about the nominal values.

Methods inherited from class edu.udo.cs.yale.example.AbstractAttribute

clearConstructionDescription, compatible, compatibleUnit, divideUnits, equalConstructionDescription, equals, getArguments, getBlockNumber, getBlockType, getConstructionDepth, getConstructionDescription, getConstructionDescription, getFunctionName, getName, getTableIndex, getUnit, getUnknownCounter, getValueType, isBlockStart, isGenerated, isInterval, isSeries, multiplyUnits, parseUnits, setArguments, setBlockNumber, setBlockType, setFunctionName, setName, setTableIndex, setUnit, setUnits, setUnknownCounter, unitToString

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

MAX_NUMBER_OF_SHOWN_NOMINAL_VALUES

private static final int MAX_NUMBER_OF_SHOWN_NOMINAL_VALUES

The maximum number of nominal values displayed in result strings.

See Also:

Constant Field Values

mode

private java.lang.String mode

The mode value for this attribute.

symbolToIndexMap

private java.util.Map<java.lang.String,java.lang.Integer> symbolToIndexMap

The map between symbolic values and their indices.

indexToSymbolMap

private java.util.List<java.lang.String> indexToSymbolMap

The map between indices of nominal values and the actual nominal value.

indexToCounterMap

private int[] indexToCounterMap

A map between symbolic values and a counter how often the value occurs in the data.

Constructor Detail

NominalAttribute

protected NominalAttribute(java.lang.String name)

Creates a simple attribute which is not part of a series and does not provide a unit string.

NominalAttribute

protected NominalAttribute(java.lang.String name,
                           int valueType)

Creates a simple attribute which is not part of a series and does not provide a unit string.

Method Detail

clone

public java.lang.Object clone()

Clones this attribute.

Specified by:

clone in interface Attribute

Specified by:

clone in class AbstractAttribute

copyProperties

public void copyProperties(Attribute attribute)

Copies all properties from the given attribute.

Specified by:

copyProperties in interface Attribute

Overrides:

copyProperties in class AbstractAttribute

writeAttributeData

public void writeAttributeData(java.io.DataOutput out)
                        throws java.io.IOException

Overrides the super method and add information about the nominal values. Writes the (non transient) attribute data to an output stream.

Specified by:

writeAttributeData in interface Attribute

Overrides:

writeAttributeData in class AbstractAttribute

Throws:

java.io.IOException

readAttributeData

public void readAttributeData(java.io.DataInput in)
                       throws java.io.IOException

Overrides the super method and reads information about the nominal values.

Specified by:

readAttributeData in interface Attribute

Overrides:

readAttributeData in class AbstractAttribute

Throws:

java.io.IOException

setMode

public void setMode(java.lang.String mode)

Sets the mode for this attribute.

getMode

public java.lang.String getMode()

Returns the mode for this attribute.

getAverage

public double getAverage()

Not supported for nominal attributes.

setAverage

public void setAverage(double a)

Not supported for nominal attributes.

getVariance

public double getVariance()

Not supported for nominal attributes.

setVariance

public void setVariance(double v)

Not supported for nominal attributes.

getMaximum

public double getMaximum()

Not supported for nominal attributes.

setMaximum

public void setMaximum(double v)

Not supported for nominal attributes.

getMinimum

public double getMinimum()

Not supported for nominal attributes.

setMinimum

public void setMinimum(double v)

Not supported for nominal attributes.

isNominal

public boolean isNominal()

Returns true if this attribute is nominal.

isNumerical

public boolean isNumerical()

Returns true if this attribute is nominal.

isBooleanClassification

public boolean isBooleanClassification()

Returns true if this attribute is nominal attribute with two different class values.

clearMaps

public void clearMaps()

Clears all mappings for nominal values.

mapString

public int mapString(java.lang.String str)

Returns the index for the nominal attribute value str. If the string is unknown, a new index value is assigned. Returns -1, if str is null.

getIndex

public int getIndex(java.lang.String str)

Returns the index of the given nominal value or -1 if this value was not mapped before by invoking the method mapIndex(int).

mapIndex

public java.lang.String mapIndex(int index)

Returns the attribute value, that is associated with this index. Index counting starts with 0. WARNING: In order to iterate over all values please use the collection returned by getValues().

replaceValue

public void replaceValue(java.lang.String oldValue,
                         java.lang.String newValue)

Replaces the old value with the new one. Ensures that the new value gets the same value index.

getValueCount

public int getValueCount(java.lang.String value)

Returns the number of occurences of the given nominal value.

setIndexToCounterMap

public void setIndexToCounterMap(int[] indexToCounterMap)

Sets the index to counter map, e.g. after recalculating the attribute statistics.

getAsString

public java.lang.String getAsString(double value,
                                    int digits)

Returns a string representation and maps value to a string if type is nominal. The number of digits is ignored.

getNegativeIndex

public int getNegativeIndex()

Returns the index of the first value if this attribute is a classification attribute, i.e. if it is binominal.

getPositiveIndex

public int getPositiveIndex()

Returns the index of the second value if this attribute is a classification attribute. Works for all binominal attributes.

getValues

public java.util.Collection<java.lang.String> getValues()

Returns the values of the attribute as an enumeration of strings.

getNumberOfValues

public int getNumberOfValues()

Returns the number of different nominal values.

isDefault

public boolean isDefault(double value)

Returns true iff value is the default value for this attribute. The default for nominal attributes is the first nominal value, i.e. the value with index 0.

sortNominalMappings

public void sortNominalMappings()

This method rearranges the string to number mappings such that they are in alphabetical order.
VERY IMPORTANT NOTE: Do not call this method when this attribute is already associated with an AbstractExampleTable and it already contains Examples. All examples will be messed up!

toString

public java.lang.String toString()

Description copied from class: AbstractAttribute

Returns a human readable string that describes this attribute.

Specified by:

toString in interface Attribute

Overrides:

toString in class AbstractAttribute

getStatisticsString

public java.lang.String getStatisticsString()

Returns a string representation of the range (numerical attribute) or class values (nominal attribute).

throwNonNumericalException

private void throwNonNumericalException(java.lang.String message)

Throws a runtime exception.

ensureClassification

private void ensureClassification()

Throws a runtime exception if this attribute is not a classification attribute.