Flatten kNN matrix to edge list

Helper function to leverage Rust to transform a kNN matrix into a flat edge list.

Usage

rs_knn_mat_to_edge_list(knn_mat, one_index)

Arguments

knn_mat

Integer matrix. Rows represent the samples and the columns the 0-based indices of the k-nearest neighbours.

one_index

Boolean. Shall 1-based indices be returned.

Value

A flat vector representing the edge list, alternating from and to, i.e. c(from_1, to_1, from_2, to_2, ...).