com.pervasive.datarush.analytics.text

Class WordMap

java.lang.Object

com.pervasive.datarush.analytics.text.NGramMap

com.pervasive.datarush.analytics.text.WordMap

public class WordMap
extends NGramMap

Implementation of a word frequency model.

Field Summary

Fields inherited from class com.pervasive.datarush.analytics.text.NGramMap

map

Constructor Summary

Constructors

Constructor and Description
WordMap() Default constructor of an empty word map.
WordMap(Map<String,Integer> map) Create a word to frequency map.
WordMap(Map<String,Integer> map, int textSize) Create a word to frequency map.
WordMap(NGramMap map) Convert a valid NGramMap into a word map.
WordMap(WordMap map) Copy a word to frequency map.

Method Summary

Modifier and Type	Method and Description
boolean	decreaseFreq(String word) Removes a word from the map or decrease the frequency if the absolute frequency is greater than one.
static TokenDecoder	getDecoder()
static TokenEncoder	getEncoder()
int	getFrequency(String word) Get the absolute frequency of a word in the map.
double	getProbability(String word) Get the relative frequency of a word in the map.
Map<String,Integer>	getStringMap() Get a copy of the map that backs this object.
List<String>	getWordList() Get an ordered list of the words contained in the map.
boolean	increaseFreq(String word) Adds a word to the map or increases the frequency if it is already present.
int	removeWord(String word) Removes a word from the map.
String	toString()

Methods inherited from class com.pervasive.datarush.analytics.text.NGramMap

calcOrigTextSize, decreaseFreq, equals, filterByThreshold, filterByTotal, getFrequency, getFrequencyList, getMap, getN, getNGramList, getOrigTextSize, getProbability, getProbabilityList, hashCode, increaseFreq, iterator, removeNGram, setOrigTextSize

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

WordMap

public WordMap()

Default constructor of an empty word map.

WordMap

public WordMap(Map<String,Integer> map)

Create a word to frequency map.

Parameters:

map - the mappings to use

WordMap

public WordMap(Map<String,Integer> map,
               int textSize)

Create a word to frequency map.

Parameters:

map - the mappings to use

textSize - the number of elements in the original text

WordMap

public WordMap(WordMap map)

Copy a word to frequency map.

Parameters:

map - the word map to copy

WordMap

public WordMap(NGramMap map)

Convert a valid NGramMap into a word map. A valid map has an N of one. If the NGramMap is invalid the WordMap will remain empty.

Parameters:

map - the n-gram map to convert

Method Detail

getWordList

public List<String> getWordList()

Get an ordered list of the words contained in the map.

Returns:

the list of words

getFrequency

public int getFrequency(String word)

Get the absolute frequency of a word in the map.

Parameters:

word - the word to get the frequency of

Returns:

the absolute frequency of the word

getProbability

public double getProbability(String word)

Get the relative frequency of a word in the map. If OrigTextSize has not been set will calculate based on the current map.

Parameters:

word - the word to get the frequency of

Returns:

the relative frequency of the word

increaseFreq

public boolean increaseFreq(String word)

Adds a word to the map or increases the frequency if it is already present.

Parameters:

word - element to increase the frequency of in the map

Returns:

true if word is valid and could be incremented

decreaseFreq

public boolean decreaseFreq(String word)

Removes a word from the map or decrease the frequency if the absolute frequency is greater than one.

Parameters:

word - element to decrease the frequency of in the map

Returns:

true if word is valid and could be decremented

removeWord

public int removeWord(String word)

Removes a word from the map.

Parameters:

word - element to remove from the map

Returns:

the frequency previously associated with the word or null

getStringMap

public Map<String,Integer> getStringMap()

Get a copy of the map that backs this object.

Returns:

map of Strings to Integers

toString

public String toString()

Overrides:

toString in class NGramMap

getEncoder

public static TokenEncoder getEncoder()

getDecoder

public static TokenDecoder getDecoder()