I have been working with diamond and megan6 on a large metagenomics dataset and am now interested in performing some analyses outside of MEGAN. I was able to export otu tables, biom files, and tree files, but some analyses (such as unifrac) require the branch lengths in the tree files. However, I cannot find the lengths in the exported files or in the default ncbi.tre. I have taken a look at the ncbi data dumps, iTOL, and a few other places but no success. Any advice? Do I compute them myself?
Sorry if this is a simple or silly question, I am new to this.