What it does
Takes a raw count expression matrix and returns a table of normalized expression values.
Normalization can be:
RPK and TPM require a two-column correspondance table gene_name - gene length where the length is specified in nucleotide. Both these metrics are relevant only for sequencing of full length RNAs.
Note: do not comment you header line if you have header line in you tabular input (ie do not start the header line with a '#' character)
Computed values may be log-transformed (log2([CPM or RPK or TPM]+1))