inst/tag/shiny/help/analyse/ngram_fit.md

In wrathematics/TAG: Text Analytics Gateway

N-Grams

An n-gram is an ordered sequence of "words" taken n at a time from a body of text. They can be very useful for discovering commonly used phrases in a text.

For example, consider the sequence of "words" (separated by at least one space)

A B A C A B B

If we examine the 2-grams (or bigrams) of this sequence, they are

A B, B A, A C, C A, A B, B B

or without repetition:

A B, B A, A C, C A, B B

That is, we take the input string and group the words 2 at a time (because we wanted to look at bigrams, so n=2). Notice that the number of n-grams and the number of words are not obviously related; counting repetition, the number of n-grams is equal to

num_words - n + 1

wrathematics/TAG documentation built on May 20, 2019, 11:37 a.m.