"baf"(object)
"chromosome"(object,...)
"isSnp"(object, ...)
"lrr"(object) baf and lrr are accessors for the B allele
frequencies and log R ratio assays (matrices or arrays), respectively,
chromosome returns the seqnames of the rowRanges.
isSnp returns a logical vector for each marker in
rowRanges indicating whether the marker targets a SNP
(nonpolymorphic regions are FALSE).
RangedSummarizedExperiment