prior.binomial: prior.binomial

In chr1swallace/snpBMA: BMA exploration of multi-SNP models in genetic association testing

Description

Binomial prior for number of SNPs in a model

Usage

  prior.binomial(x = 1:n, n = length(groups), expected,
    groups = NULL, pi0 = 0.2, value = c("odds", "prob"))

Arguments

x	number of SNPs in a model (defaults to 1:length(groups), ie returns a vector)
n	total number of SNPs or SNP groups available
expected	expected number of SNPs in a model
groups	groups of SNPs, from which at most one SNP should be selected
pi0	prior probability that no SNP is associated
value	"odds" or "prob" for prior odds (relative to pi0) or prior probabilities

Value

prior probability/ies or odds as a numeric

Author(s)

Chris Wallace

Examples

n<-100 # 100 SNPs in region
x <- 1:10 # consider prior for up to 10 causal SNPs
xbar <- 3 # expect around 3 causal

## a binomial prior
y <- prior.binomial(x, n, xbar)
plot(x, y, type="h")

chr1swallace/snpBMA documentation built on May 13, 2019, 6:19 p.m.