Log number of possible linkage configurations

Computes log(nB! / (nB - sumD)!), i.e. the log number of ways to choose sumD ordered links among n_records_B records of the larger file; used in log_lik() to normalise the likelihood of the linkage matrix.

Usage

log_possible_config(n_records_B, sumD)

Arguments

n_records_B

Integer, number of records in the larger data source (B).

sumD

Integer, number of currently linked records.

Value

Numeric, sum(log((n_records_B - sumD + 1):n_records_B)), or 0 if sumD == 0.

Examples

log_possible_config(n_records_B = 15, sumD = 5)
#> [1] 12.79486