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BREADR (version 1.0.3)

callRelatedness: callRelatedness

Description

A function that takes PMR observations, and (given a prior distribution for degrees of relatedness) returns the posterior probabilities of all pairs of individuals being (a) the same individual/twins, (b) first-degree related, (c) second-degree related or (d) "unrelated" (third-degree or higher). The highest posterior probability degree of relatedness is also returned as a hard classification. Options include setting the background relatedness (or using the sample median), a minimum number of overlapping SNPs if one uses the sample median for background relatedness, and a minimum number of overlapping SNPs for including pairs in the analysis.

Usage

callRelatedness(
  pmr_tibble,
  class_prior = rep(0.25, 4),
  average_relatedness = NULL,
  median_co = 500,
  filter_n = 1
)

Value

results_tibble: A tibble containing 13 columns:

  • row: The row number

  • pair: the pair of individuals that are compared.

  • relationship: the highest posterior probability estimate of the degree of relatedness.

  • pmr: the pairwise mismatch rate (mismatch/nsnps).

  • sd: the estimated standard deviation of the pmr.

  • mismatch: the number of sites which did not match for each pair.

  • nsnps: the number of overlapping snps that were compared for each pair.

  • ave_re;: the value for the background relatedness used for normalisation.

  • Same_Twins: the posterior probability associated with a same individual/twins classification.

  • First_Degree: the posterior probability associated with a first-degree classification.

  • Second_Degree: the posterior probability associated with a second-degree classification.

  • Unrelated: the posterior probability associated with an unrelated classification.

  • BF: A strength of confidence in the Bayes Factor associated with the highest posterior probability classification compared to the 2nd highest. (No longer included)

Arguments

pmr_tibble

a tibble that is the output of the processEigenstrat function.

class_prior

the prior probabilities for same/twin, 1st-degree, 2nd-degree, unrelated, respectively.

average_relatedness

a single numeric value, or a vector of numeric values, to use as the average background relatedness. If NULL, the sample median is used.

median_co

if average_relatedness is left NULL, then the minimum cutoff for the number of overlapping snps to be included in the median calculation is 500.

filter_n

the minimum number of overlapping SNPs for which pairs are removed from the entire analysis. If NULL, default is 1.

Examples

Run this code
callRelatedness(counts_example,
  class_prior=rep(0.25,4),
  average_relatedness=NULL,
  median_co=5e2,filter_n=1
)

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