Where I have either an NMDS or a PCOA biplot (or loading plot I've seen it called), where the arrows represent the strength and direction of certain metadata variables that explain microbiome variation. In my case I have a factor, diet, where I would like different arrows representing the levels of my diet factor. So an herbivory arrow, a carnivory arrow and so forth, pointing to each cluster on my PCOA. I've seen ways to do this for numerical variables but not categorical. If anyone can point me in the right direction I would be forever indebted!
Cheers,
Sam
I think my first recommendation would be to see if you can identify labeling based on the available tools. That, said, you could probably trick the system if you code your categorical variables as 0 and 1. (I tend to use Patsy in python; there may be something similar in R or your other favorite software.) Import that table as FeatureTable[Frequency], convert to relative frequency and then maybe look at what your options are with qiime diversity pcoa-biplot.
I might also look at options in emperor itself without the biplot. You can show about 3 metadata categories pretty easily (color, size, shape). You could also try side by side biplots colored by different variables.
