org.egothor.parser.filter
Class WordNGrammer

java.lang.Object
  org.egothor.core.Filter
      org.egothor.parser.filter.WordNGrammer

All Implemented Interfaces:

Sequence<Token>

public class WordNGrammer
extends Filter

This class produces N-grams of words. From a sentence with W words w1, w2, w3,... wW it produce W - N + 1 N-grams. The N is determined by the Constants.WORDNGRAMS_LENGHT constant. Filter treats all types of input tokens equally.

Output tokens:

• name - <NGRAM>
• text - concatenation of texts of tokens belonging to the N-gram, with space separator
• weight - arithmetic mean of all tokens belonging to the N-gram
• colS, lineS - taken from the first token belonging to the N-gram
• colE, lineE - taken from the last token belonging to the N-gram
• sentence, paragraph, sentenceInParagraph - taken from first token, are equal for all tokens belonging to the N-gram
• reloffset - taken from the first token belonging to the N-gram

Example (N=3):
Sentence: "the dog smelled like a skunk"
N-grams: "<NGRAM>the dog smelled", "<NGRAM>dog smelled like", "<NGRAM>smelled like a", "<NGRAM>like a skunk"

Typically the filter ParagraphPunctFilter shall be applied to the token sequence before this filter. If it is not, than all the document is taken as one sentence and N-grams are produced "on document level". This filter should be the last filter to apply. The filter has an inner context thus it cannot be shared in a filtering chain.

Author:

Kate�ina Dufkov�

Field Summary

Fields inherited from class org.egothor.core.Filter

prev

Constructor Summary

WordNGrammer(Sequence<Token> prev)
Constructor for the WordNGrammer object

Method Summary

Token

next() Return the next token.

Methods inherited from class org.egothor.core.Filter

action, getPrevTokenizer, setPrevTokenizer

Methods inherited from class java.lang.Object

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

Constructor Detail

WordNGrammer

public WordNGrammer(Sequence<Token> prev)

Constructor for the WordNGrammer object

Parameters:

prev - tokenizer used by the filter

Method Detail

next

public Token next()

Return the next token.

Specified by:

next in interface Sequence<Token>

Overrides:

next in class Filter

Returns:

the next token

See Also:

Filter.next()