Get root taxa

Return the root taxa for a taxonomy() or taxmap() object. Can also be used to get the roots of a subset of taxa.

obj$roots(subset = NULL, value = "taxon_indexes")
roots(obj, subset = NULL, value = "taxon_indexes")

Arguments

obj	The taxonomy() or taxmap() object containing taxon information to be queried.
subset	Taxon IDs, TRUE/FALSE vector, or taxon indexes to find roots for. Default: All taxa in obj will be used. Any variable name that appears in all_names() can be used as if it was a vector on its own.
value	What data to return. This is usually the name of column in a table in obj$data. Any result of all_names(obj) can be used, but it usually only makes sense to data that corresponds to taxa 1:1, such as taxon_ranks(). By default, taxon indexes are returned.

Value

character

See also

Other taxonomy indexing functions: branches(), internodes(), leaves(), stems(), subtaxa(), supertaxa()

Examples

# Return indexes of root taxa
roots(ex_taxmap)
#> b c 
#> 1 2 

# Return indexes for a subset of taxa
roots(ex_taxmap, subset = 2:17)
#> c d e f 
#> 2 3 4 5 

# Return something besides taxon indexes
roots(ex_taxmap, value = "taxon_names")
#>          b          c 
#> "Mammalia"  "Plantae"