TPM格式搜索错了，好尴尬

## functions for rpkm and tpm
## from https://gist.github.com/slowkow/c6ab0348747f86e2748b#file-counts_to_tpm-r-L44
## from https://www.biostars.org/p/171766/
rpkm <- function(counts, lengths) {
  rate <- counts / lengths
  rate / sum(counts) * 1e9
}

tpm <- function(counts, lengths) {
  rate <- counts / lengths
  rate / sum(rate) * 1e6
}

rpkm <- function(counts, lengths) {
  rate <- counts / lengths
  rate / sum(counts) * 1e9
}

exprSet_rpkm=rpkm(exprSet,len) 
exprSet_tpm=1e6*exprSet_rpkm/colSums(exprSet_rpkm)