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hscovar (version 0.4.2)

Calculation of Covariance Between Markers for Half-Sib Families

Description

The theoretical covariance between pairs of markers is calculated from either paternal haplotypes and maternal linkage disequilibrium (LD) or vise versa. A genetic map is required. Grouping of markers is based on the correlation matrix and a representative marker is suggested for each group. Employing the correlation matrix, optimal sample size can be derived for association studies based on a SNP-BLUP approach. The implementation relies on paternal half-sib families and biallelic markers. If maternal half-sib families are used, the roles of sire/dam are swapped. Multiple families can be considered. Wittenburg, Bonk, Doschoris, Reyer (2020) "Design of Experiments for Fine-Mapping Quantitative Trait Loci in Livestock Populations" . Carlson, Eberle, Rieder, Yi, Kruglyak, Nickerson (2004) "Selecting a maximally informative set of single-nucleotide polymorphisms for association analyses using linkage disequilibrium" .

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Version

Install

install.packages('hscovar')

Monthly Downloads

165

Version

0.4.2

License

GPL (>= 2)

Maintainer

D<c3><b6>rte Wittenburg

Last Published

April 13th, 2021

Functions in hscovar (0.4.2)

calcvar

Variance of estimator
startvalue

Start value for estimating optimal sample size
coeff.beta.k

Ratio of expected value to variance of estimator
tagSNP

tagSNP
Haplo2Geno

Conversion of haplotypes into genotypes
H.sire

testdata: sire haplotypes
testdata

Description of the testdata
matLD

testdata: maternal linkage disequilibrium
AR1

Correlation matrix of an autoregressive model of order 1
LDdam

Calculation of maternal LD matrix
pwr.normtest

Probability under alternative hypothesis (power)
LDsire

Calculation of paternal LD matrix
ExpectMat

Expected value of paternally inherited allele
CovarMatrix

Calculation of covariance matrices from maternal and paternal LD
pos.chr

testdata: genetic map positions
search.best.n.bisection

Method of bisection for estimating optimal sample size
simpleM

Calculation of effective number of independent tests
CovMat

Calculation of covariance or correlation matrix
pwr.snpblup

Wrapper function for sample size calculation