Computes list of n-gram elements positions in sequence.

get_ngrams_ind(len_seq, n, d)

Arguments

len_seq

integer value describing sequence's length.

n

integer size of n-gram.

d

integer vector of distances between elements of n-gram (0 means consecutive elements). See Details.

Value

A list with number of elements equal to n. Every element is a vector containing locations of given n-gram letter. For example, first element of list contain indices of first letter of all n-grams. The attribute d of output contains distances between letter used to compute locations (see Details).

Details

A format of d vector is discussed in Details of count_ngrams.

Examples

# positions trigrams in sequence of length 10 get_ngrams_ind(10, 9, 0)
#> [[1]] #> [1] 1 2 #> #> [[2]] #> [1] 2 3 #> #> [[3]] #> [1] 3 4 #> #> [[4]] #> [1] 4 5 #> #> [[5]] #> [1] 5 6 #> #> [[6]] #> [1] 6 7 #> #> [[7]] #> [1] 7 8 #> #> [[8]] #> [1] 8 9 #> #> [[9]] #> [1] 9 10 #> #> attr(,"d") #> [1] 0 0 0 0 0 0 0 0