com.optimaize.langdetect.ngram

Class NgramExtractor

java.lang.Object

com.optimaize.langdetect.ngram.NgramExtractor

public class NgramExtractor
extends Object

Class for extracting n-grams out of a text.

Author:

Fabian Kessler

Method Summary

Methods

Modifier and Type	Method and Description
Map<String,Integer>	extractCountedGrams(CharSequence text)
List<String>	extractGrams(CharSequence text) Creates the n-grams for a given text in the order they occur.
NgramExtractor	filter(NgramFilter filter)
List<Integer>	getGramLengths()
static NgramExtractor	gramLength(int gramLength)
static NgramExtractor	gramLengths(Integer... gramLength)
NgramExtractor	textPadding(char textPadding) To ensure having border grams, this character is added to the left and right of the text.

Methods inherited from class java.lang.Object

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

Method Detail

gramLength

public static NgramExtractor gramLength(int gramLength)

gramLengths

public static NgramExtractor gramLengths(Integer... gramLength)

filter

public NgramExtractor filter(NgramFilter filter)

textPadding

public NgramExtractor textPadding(char textPadding)

To ensure having border grams, this character is added to the left and right of the text.

Example: when textPadding is a space ' ' then a text input "foo" becomes " foo ", ensuring that n-grams like " f" are created.

If the text already has such a character in that position (eg starts with), it is not added there.

Parameters:

textPadding - for example a space ' '.

getGramLengths

public List<Integer> getGramLengths()

extractGrams

@NotNull
public List<String> extractGrams(@NotNull
                                CharSequence text)

Creates the n-grams for a given text in the order they occur.

Example: extractSortedGrams("Foo bar", 2) => [Fo,oo,o , b,ba,ar]

Parameters:

text -

Returns:

The grams, empty if the input was empty or if none for that gramLength fits.

extractCountedGrams

@NotNull
public Map<String,Integer> extractCountedGrams(@NotNull
                                              CharSequence text)

Returns:

Key = ngram, value = count The order is as the n-grams appeared first in the string.