Group the samples
Examples
urt_by_loc <- urt %>% group_samples(location)
# apply a function to each separate taco, eg. tacosum
urt_by_loc@tacos %>% lapply(tacosum)
#> $N
#> n_samples n_taxa n_reads
#> 86 1197 1852959
#>
#> $NF
#> n_samples n_taxa n_reads
#> 131 1244 2020519
#>
# subset urt to keep only nasopharynx samples
urt_nf <- urt_by_loc@tacos$NF