The function computes groups based on the number of bands per sample
in a RFLP data set. Each group comprises RFLP-samples with equal
number of bands.
References
Flessa, F., Kehl, A., Kohl, M.
Analysing diversity and community structures using PCR-RFLP: a new software application.
Molecular Ecology Resources 2013 Jul; 13(4):726-33.