Kinship index

The weight of two DNA profiles for a stated relationship against no relationship, locus by locus and overall. Loci are taken as independent; there is no allowance for mutation or coancestry. See proof("kinidx").

Usage

kinidx(g1, g2, freq, rel = "parent")

Arguments

g1, g2

The two genotypes: two-column matrices of allele labels, one row per locus (row names name the loci), or two alleles for one locus.

freq

The population frequencies of the alleles of g1, same shape. When g1, g2 and freq all have row names, their rows are matched to g1 by locus name (an error lists loci that differ); otherwise by position, so only names protect against a mismatch.

rel

The relationship: "parent", "sibling", "half" (half siblings, grandparent or uncle) or "cousin", or the three probabilities of sharing 0, 1 and 2 alleles by descent. Names are matched exactly, in lower case.

Value

A list: locus, a data frame with locus and idx; log10idx, the base-10 logarithm of the combined index; and post, the probability of the relationship at even prior odds.

Examples

kinidx(g1 = c(12, 14), g2 = c(12, 14), freq = c(0.1, 0.2), rel = "sibling")
#> $locus
#>   locus   idx
#> 1     1 8.375
#> 
#> $log10idx
#> [1] 0.9229848
#> 
#> $post
#> [1] 0.8933333
#>