Count only observed k-mers. Biostrings::oligonucleotideFrequency reports all possible k-mers. For k > 12, the memory for creating empty k-mer counts spiked and crashed the R session.
countKmers(sequences, k)
A vector of k-mer counts. The counts of multiple sequences are combined, similar to Biostrings::oligonucleotideFrequency simplify.as "collapsed".
Sequence strings.
Size of k-mer.