When `filter_obs` removes taxa should it remove data for those taxa from other data sets?

[zachary-foster]

Currently, running filter_obs(obj, "my_data_set", some_condition, drop_taxa = TRUE) will remove taxa that no occur in "my_data_set" from the taxmap object, but it does not remove data in other data sets associated with removed taxa, so those end up with invalid taxon IDs.

1. Only remove taxa that no longer appear in ALL data sets. The user could then use filter_taxa to remove all taxa from all data sets that don't appear in one of the data sets.
2. Remove taxa from ALL data sets that are removed when filtering a single data set.

Perhaps 1 could be the default behavior and 2 could be optional. Maybe drop_other_obs = TRUE.

Either way, filter_obs should not be allowed to return an invalid taxmap object like it can now.

[zachary-foster]

Solved this by using filter_taxa in filter_obs. I dont think filter_obs cannot return invalid taxmap objects now