扩展两个方向的范围

这很简单.你可以使用start和end功能GenomicRanges.

gr <- GRanges(c('chr1','chr1'), IRanges(start=c(20, 120), +')
gr
# GRanges object with 2 ranges and 0 metadata columns:
#       seqnames     ranges strand
#              
#   [1]     chr1 [ 20,  29]      +
#   [2]     chr1 [120, 129]      +
#   -------
#   seqinfo: 1 sequence from an unspecified genome; no seqlengths

start(gr) <- start(gr) - 10
end(gr) <- end(gr) + 10
gr
# GRanges object with 2 ranges and 0 metadata columns:
#      seqnames     ranges strand
#             
#  [1]     chr1 [ 10,  39]      +
#  [2]     chr1 [110, 139]      +
#  -------
#  seqinfo: 1 sequence from an unspecified genome; no seqlengths