Are gneiss and q2-longitudinal correlation or regression methods?

[Nicholas_Bokulich]

Thanks for the in-depth research and suggestions @jjmmii! The short answer is no, QIIME 2 does not have any methods similar to what you are describing. A new plugin or plugin action wrapping the R compositions package would be really useful to the community, and a good way for an experienced R user to contribute code to QIIME 2

I have raised an issue to track that feature request.

@jjmmii

linear-mixed-effects uses Kendall correlation (line 251 in the code

That line of code is not part of linear-mixed-effects, which uses LME. That code is for NMIT, which is really using Kendall correlation in an entirely different way (it is correlating subjects' longitudinal compositions to calculate distance, not correlating species abundance with a user-defined variable).

@jjmmii

This leads me to another question: Is gneiss and linear mixed effects a type of regression or correlation?

gneiss is a regression method, but maybe @mortonjt would like to elaborate more.

I hope that clarifies!