documentation_clusters
A numeric factor assigning samples to clusters.
Number of clusters. Default: 5L
Which taxa rank to use. E.g. "Phylum",
"Genus", ".otu", etc. An integer can also be
given, where 1 is the highest rank, 2 is the second
highest, -1 is the lowest rank, -2 is the second
lowest, and 0 is the OTU "rank". Run biom$ranks to
see all options for a given rbiom object. Default: .otu.