auk (version 0.8.0)

auk_state: Filter the eBird data by state

Description

Define a filter for the eBird Basic Dataset (EBD) based on a set of states. This function only defines the filter and, once all filters have been defined, auk_filter() should be used to call AWK and perform the filtering.

Usage

auk_state(x, state, replace = FALSE)

Value

An auk_ebd object.

Arguments

x

auk_ebd or auk_sampling object; reference to file created by auk_ebd() or auk_sampling().

state

character; states to filter by. eBird uses 4 to 6 character state codes consisting of two parts, the 2-letter ISO country code and a 1-3 character state code, separated by a dash. For example, "US-NY" corresponds to New York State in the United States. Refer to the data frame ebird_states for look up state codes.

replace

logical; multiple calls to auk_state() are additive, unless replace = FALSE, in which case the previous list of states to filter by will be removed and replaced by that in the current call.

Details

It is not possible to filter by both country and state, so calling auk_state() will reset the country filter to all countries, and vice versa.

This function can also work with on an auk_sampling object if the user only wishes to filter the sampling event data.

See Also

Other filter: auk_bbox(), auk_bcr(), auk_breeding(), auk_complete(), auk_country(), auk_county(), auk_date(), auk_distance(), auk_duration(), auk_exotic(), auk_extent(), auk_filter(), auk_last_edited(), auk_observer(), auk_project(), auk_protocol(), auk_species(), auk_time(), auk_year()

Examples

# state codes for a given country can be looked up in ebird_states
dplyr::filter(ebird_states, country == "Costa Rica")
# choose texas, united states and puntarenas, cost rica
states <- c("US-TX", "CR-P")
system.file("extdata/ebd-sample.txt", package = "auk") %>%
  auk_ebd() %>%
  auk_state(states)
  
# alternatively, without pipes
ebd <- auk_ebd(system.file("extdata/ebd-sample.txt", package = "auk"))
auk_state(ebd, states)