B2M {ENmix} | R Documentation |
Convert methylation beta value to M value.
B2M(x)
x |
An numeric matrix with values between 0 and 1 |
Methylation beta value is calculated as beta=M/(M+U+a). M is methylated intensity, U is unmethylated intensity, and a is a constant offset (by default , a=100). M value is calculated as M=log2((M+a)/(U+a)). M or U is usually greater than 1000, so a is negligible for most probes. if a=0, then M=log2(beta)/(1-beta).
A matrix of M values
Zongli Xu
if (require(minfiData)){ path <- file.path(find.package("minfiData"),"extdata") rgSet <- readidat(path = path,recursive = TRUE) mdat=getmeth(rgSet) beta=getB(mdat,"Illumina") m=B2M(beta) }