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Create stationary periods from twilight midpoints

Source: R/tag_stap_daily.R
tag_stap_daily.Rd

Build a stap table using midpoints between consecutive twilight pairs so the period lengths follow the twilight drift. If a stap0 is provided (as a data.frame or a CSV path), its intervals are kept as-is and the remaining gaps are filled using twilight midpoints.

Usage

tag_stap_daily(
  tag,
  stap0 = NULL,
  twl_grouping = "night",
  max_twl_gap_hours = 23.5,
  quiet = FALSE
)

Arguments

tag

a GeoPressureR tag object with twilight.

stap0

optional stap data.frame with columns start and end, a CSV path with those columns (POSIXct-compatible strings), or a tag id resolved by read_stap().

twl_grouping

Which period is assumed to be when the bird is moving: "night" (default) assumes the bird is moving during the night, so sunrise-to-sunset twilights are combined into the same stationary period, while "day" assumes the bird is moving during the day, so sunset-to-sunrise twilights are combined into the same stationary period.

max_twl_gap_hours

maximum allowed gap between consecutive twilights (in hours) before erroring, indicating missing twilights.

quiet

logical to hide messages.

Value

Updated tag with a twilight-based stap and optional stap0. The stap includes a logical column stap0 set to TRUE when intervals come from the provided stap0 input.

See also

Other tag: print.tag(), read_stap(), tag_create(), tag_set_map()

Examples

withr::with_dir(system.file("extdata", package = "GeoPressureR"), {
  tag <- tag_create("18LX", quiet = TRUE) |>
    tag_label(quiet = TRUE) |>
    twilight_create() |>
    twilight_label_read()
})
tag <- tag_stap_daily(tag, twl_grouping = "night")
#> Warning: The `tag` object already has a stap defined which will be overwriten.