eBird checklists can be shared among a group of multiple observers, in which
case observations will be duplicated in the database. This functions removes
these duplicates from the eBird Basic Dataset (EBD) or the EBD sampling event
data (with checklists_only = TRUE), creating a set of unique bird
observations. This function is called automatically by read_ebd() and
read_sampling().
auk_unique(
x,
group_id = "group_identifier",
checklist_id = "sampling_event_identifier",
species_id = "scientific_name",
observer_id = "observer_id",
checklists_only = FALSE
)data.frame; the EBD data frame, typically as imported by
read_ebd().
character; the name of the group ID column.
character; the name of the checklist ID column, each
checklist within a group will get a unique value for this field. The record
with the lowest checklist_id will be picked as the unique record within
each group. In the output dataset, this field will be updated to have a
full list of the checklist IDs that went into this group checklist.
character; the name of the column identifying species uniquely. This is required to ensure that removing duplicates is done independently for each species. Note that this will not treat sub-species independently and, if that behavior is desired, the user will have to generate a column uniquely identifying species and subspecies and pass that column's name to this argument.
character; the name of the column identifying the owner
of this instance of the group checklist. In the output dataset, the full
list of observer IDs will be stored (comma separated) in the new
observer_id field. The order of these IDs will match the order of the
comma separated checklist IDs.
logical; whether the dataset provided only contains
checklist information as with the sampling event data file. If this
argument is TRUE, then the species_id argument is ignored and removing
of duplicated records is done at the checklist level not the species level.
A data frame with unique observations, and an additional field,
checklist_id, which is a combination of the sampling event and group IDs.
This function chooses the checklist within in each that has the
lowest value for the field specified by checklist_id. A new column is
also created, checklist_id, whose value is the taken from the field
specified in the checklist_id parameter for non-group checklists and from
the field specified by the group_id parameter for grouped checklists.
All the checklist and observer IDs for the checklists that comprise a given group checklist will be retained as a comma separated string ordered by checklist ID.
Other pre:
auk_rollup()
# read in an ebd file and don't automatically remove duplicates
f <- system.file("extdata/ebd-sample.txt", package = "auk")
ebd <- read_ebd(f, unique = FALSE)
# remove duplicates
ebd_unique <- auk_unique(ebd)
nrow(ebd)
#> [1] 400
nrow(ebd_unique)
#> [1] 398