a character vector determining type of pairwise comparsion. Can
be "strata" for strata or "ids" for individuals.
num.cores
number of CPU cores to use. Defaults to the number reported
by detectCores - 1.
smry
a character vector determining type of summary for
sharedAlleles. "which" returns the names of the alleles shared.
"num" returns the number of alleles shared.
ids
character vector of two sample ids to compare.
id.row.mat
lookup matrix of id row names or numbers of a format like the one
generated by idRows.