I have a quick question. I would like to plot some bar graphs to understand the community composition. Is the feature table need to be rarefied prior to plotting taxa bar plot where y axis is relative abundance (%)? As per my understanding, rarefaction is a means of normalization. Once feature table is rarefied, all samples will have the same sampling depth (i.e. 3000 sequences), which means total abundance of each sample will be the same. If I plot taxa bar plot using rarefied data
with abundance (# reads) as y axis, the plot should be exactly same as the one plotted with un-rarefied data with relative abundance (frequency) as y axis, is that right? In this sense, rarefying is equivalent and interchangeable with calculating relative abundance, and once one is done, no need to do the other. Is this correct? Thank you so much.