match_n_to_m function

Force n to m matching on a set of pairs

match_n_to_m(x, y, w, n = 1, m = 1)

Arguments

• x: a vector of identifiers for each x in each pair This vector should have a unique value for each element in x.
• y: a vector of identifiers for each y in each pair This vector should have a unique value for each element in y.
• w: a vector with weights for each pair. The algorithm will try to maximise the total weight of the selected pairs.
• n: an integer. Each element of x can be linked to at most n elements of y.
• m: an integer. Each element of y can be linked to at most m elements of x.

Returns

A logical vector with the same length as x indicating the selected records.

Details

The algorithm will try to select pairs in such a way each element of x

is matched to at most n elements of y and that each element of y is matched at most m elements of x. It tries to select elements in such a way that the total weight w of the selected elements is maximised.

Examples

d <- data.frame(x=c(1,1,1,2,2,3,3), y=c(1,2,3,4,5,6,7), w=1:7)
# One-to-one matching:
d[match_n_to_m(d$x, d$y, d$w), ]

# N-to-one matching:
d[match_n_to_m(d$x, d$y, d$w, n=999), ]

# One-to-m matching:
d[match_n_to_m(d$x, d$y, d$w, m=999), ]

# N-to-M matching, e.g. select all pairs
d[match_n_to_m(d$x, d$y, d$w, n=999, m=999), ]