nltk.collocations.QuadgramCollocationFinder

class nltk.collocations.QuadgramCollocationFinder

Bases: AbstractCollocationFinder

A tool for the finding and ranking of quadgram collocations or other association measures. It is often useful to use from_words() rather than constructing an instance directly.

default_ws = 4

__init__(word_fd, quadgram_fd, ii, iii, ixi, ixxi, iixi, ixii)

Construct a QuadgramCollocationFinder, given FreqDists for appearances of words, bigrams, trigrams, two words with one word and two words between them, three words with a word between them in both variations.

classmethod from_words(words, window_size=4)

score_ngram(score_fn, w1, w2, w3, w4)

above_score(score_fn, min_score)

Returns a sequence of ngrams, ordered by decreasing score, whose scores each exceed the given minimum score.

apply_freq_filter(min_freq)

Removes candidate ngrams which have frequency less than min_freq.

apply_ngram_filter(fn)

Removes candidate ngrams (w1, w2, …) where fn(w1, w2, …) evaluates to True.

apply_word_filter(fn)

Removes candidate ngrams (w1, w2, …) where any of (fn(w1), fn(w2), …) evaluates to True.

classmethod from_documents(documents)

Constructs a collocation finder given a collection of documents, each of which is a list (or iterable) of tokens.

nbest(score_fn, n)

Returns the top n ngrams when scored by the given function.

score_ngrams(score_fn)

Returns a sequence of (ngram, score) pairs ordered from highest to lowest score, as determined by the scoring function provided.