gtmp
Genotype match probability
gtmp(p, q = NULL, hom = FALSE, theta = 0)crimlab.gtmp(p, q=None, hom=None, theta=None)crimlab gtmp --p VALUE [--q VALUE] [--hom VALUE] [--theta VALUE]The chance that an unrelated person from the same population shares a DNA
profile, locus by locus and overall. With theta = 0 this is the product
rule (p^2 for a homozygote, 2pq for a heterozygote). A positive theta
applies the Balding-Nichols correction for shared ancestry. That never
makes a homozygote match rarer than the product rule says; it can make a
heterozygote match rarer when both alleles are common. See
proof("gtmp").
Parameters
Section titled “Parameters”pFrequency of the first allele at each locus: numbers above 0 and at most 1, optionally named by locus, as a numeric vector, a 1-d table, a list of single numbers or a one-row data frame.
qFrequency of the second allele at each locus; not read where
homisTRUE. Named inputs are matched topby locus name, unnamed ones by position (only names protect against a mismatch).homTRUEwhere the genotype is homozygous: one value, or one per locus, matched topby name when both are named.thetaThe coancestry coefficient: one number from 0 up to, not including, 1.
Returns
Section titled “Returns”A list: locus, a data frame with locus, hom and mp;
log10mp, the base-10 logarithm of the profile match probability; and
log10lr, the same with the sign changed, the weight of a single-source
match against an unrelated alternative.
References
Section titled “References”Balding, D. J. and Nichols, R. A. (1994). DNA profile match probability calculation. Forensic Science International, 64(2-3), 125-140. doi:10.1016/0379-0738(94)90222-4
Examples
Section titled “Examples”gtmp(p = c(D3 = 0.1, vWA = 0.2), q = c(0.3, NA), hom = c(FALSE, TRUE), theta = 0.03)Generated from the R help page: gtmp in the R reference.