The output from dist_long
with an additional column containing
a factor, with levels composed of joining the categories in the group
colum of the metadata data.frame for each pairwise comparison. For example,
if one row has distance between samples id1 and id2, and in the grouping column
of the metadata id1 is identified as part of group 'A', and id2 is identified
as part of group 'B', then the output from that row will 'AB'. If they were
from the same group, say 'A', the output would be just 'A'. In this way
it is easy to identify pairs of isolates that are from the same group, and
pairs of isolates that are from different groups.