Map genera to NCBI taxonomy

[lwaldron]

• Create a function that takes a vector of genera and returns another vector of the same length and order, providing NCBI taxid wherever possible and wherever unknown.
• save taxids in the package dataset
• create a minimal unit test that checks a small vector of known mappings that also includes a couple things that can't be mapped.

You could use Bioconductor's GenomeInfoDbData for the mapping.

[lwaldron]

Comments from https://waldronlab.slack.com/archives/C016AL6G2R0

From Sean Davis:

• Download: https://ftp.ncbi.nlm.nih.gov/pub/taxonomy/new_taxdump/new_taxdump.tar.gz
• Uncompress
• Use the names column from the names.dmp file (just delimited text format) for lower case string matching.

This file includes names, synonyms, and a few other details. As far as I know, it is the most complete list available and includes all levels of the taxonomy.

From Ludwig Geistlinger:

• A convenient way might be taxize::get_ids with db = "ncbi"