poolHelper (version 1.1.0)

simulateCoverage: Simulate total number of reads per site

Description

This function simulates the total number of reads, for each polymorphic site using a negative binomial distribution.

Usage

simulateCoverage(mean, variance, nSNPs = NA, nLoci = NA, genotypes = NA)

Value

a list with the total coverage per population and per site. Each list entry is a matrix corresponding to a different locus. For each matrix, different rows represent different populations and each column is a different site.

Arguments

mean

an integer that defines the mean depth of coverage to simulate. Please note that this represents the mean coverage across all sites. If a vector is supplied instead, the function assumes that each entry of the vector is the mean for a different population.

variance

an integer that defines the variance of the depth of coverage across all sites. If a vector is supplied instead, the function assumes that each entry of the vector is the variance for a different population.

nSNPs

an integer representing the number of polymorphic sites per locus to simulate. This is an optional input but either this or the genotypes list must be supplied.

nLoci

an optional integer that represents how many independent loci should be simulated.

genotypes

a list of simulated genotypes, where each entry is a matrix corresponding to a different locus. At each matrix, each column is a different SNP and each row is a different individual. This is an optional input but either this or the nSNPs must be supplied.

Details

The total number of reads is simulated with a negative binomial and according to a user-defined mean depth of coverage and variance. This function is intended to work with a list of genotypes, simulating the depth of coverage for each site present in the genotypes. However, it can also be used to simulate coverage distributions independent of genotypes, by choosing how many loci to simulate (with the nLoci option) and choosing how many sites per locus should be simulated (with the nSNPs option).

Examples

# simulate 10 loci, each with 10 SNPs for a single population
simulateCoverage(mean = 100, variance = 250, nSNPs = 10, nLoci = 10)

# simulate 10 loci, each with 10 SNPs for two populations:
# the first with 100x and the second with 50x
simulateCoverage(mean = c(100, 50), variance = c(250, 150), nSNPs = 10, nLoci = 10)

# simulate coverage given a set of genotypes
# run scrm and obtain genotypes
genotypes <- run_scrm(nDip = 100, nloci = 10)
# simulate coverage
simulateCoverage(mean = 50, variance = 200, genotypes = genotypes)