clevr (version 0.1.2)

canonicalize_pairs: Canonicalize element pairs

Description

Coerce a collection of element pairs into canonical form. Facilitates testing of equivalence.

Usage

canonicalize_pairs(pairs, ordered = FALSE)

Value

Returns the element pairs in canonical form, so that:

• the first element id precedes the second element id lexicographically if ordered = FALSE---i.e. pair (3, 2) becomes pair (2, 3);

• pairs with missing element ids are removed;

• duplicate pairs are removed; and

• the rows in the matrix/data.frame pairs are sorted lexicographically by the first element id, then by the second element id.

Arguments

pairs

a matrix or data.frame of element pairs where rows correspond to element pairs and columns correspond to element identifiers.

ordered

whether to treat the element pairs as ordered---i.e. whether pair \((x, y)\) is distinct from pair \((y, x)\) for \(x \neq y\). Defaults to FALSE, which is appropriate for clustering, undirected link prediction, record linkage etc.

Examples

messy_pairs <- rbind(c(2,1), c(1,2), c(3,1), c(1,2))
clean_pairs <- canonicalize_pairs(messy_pairs)
all(rbind(c(1,2), c(1,3)) == clean_pairs) # duplicates removed and order fixed