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Generate a bus-route sampling frame

Source: R/schedule-generators.R
generate_bus_schedule.Rd

Converts a creel schedule calendar and circuit definitions into a sampling frame tibble with inclusion_prob and p_period columns ready for creel_design(survey_type = "bus_route").

Inclusion probability formula: inclusion_prob = p_site * p_period where p_period = crew / n_circuits.

n_circuits is the number of distinct circuit values in sampling_frame (or 1 when circuit is NULL). crew is the number of field crews deployed simultaneously.

Usage

generate_bus_schedule(
  schedule,
  sampling_frame,
  site,
  p_site,
  circuit = NULL,
  crew,
  seed = NULL
)

Arguments

schedule

A creel_schedule tibble from generate_schedule(). Currently unused in computation but required to ensure the caller has built a valid schedule before constructing the sampling frame.

sampling_frame

A data frame with site and p_site columns (and optionally circuit).

site

Column in sampling_frame giving site identifiers (tidy selector: bare name, quoted string, or tidyselect helper).

p_site

Column in sampling_frame giving per-site selection probability within the circuit. Values must sum to 1.0 per circuit (tolerance 1e-6).

circuit

Optional column giving circuit assignment. If NULL, all sites are treated as a single circuit.

crew

Integer scalar: number of crews in the field simultaneously.

seed

Optional integer seed (reserved for future randomised designs; currently unused as the function is deterministic).

Value

A tibble: sampling_frame columns plus p_period and inclusion_prob. inclusion_prob = p_site * p_period.

See also

Other "Scheduling": attach_count_times(), generate_count_times(), generate_progressive_start(), generate_schedule(), new_creel_schedule(), read_schedule(), validate_creel_schedule(), write_schedule()

Examples

sched <- generate_schedule(
  start_date    = "2024-06-01",
  end_date      = "2024-06-14",
  n_periods     = 1,
  sampling_rate = c(weekday = 0.3, weekend = 0.6),
  seed          = 42
)
frame <- data.frame(
  site   = c("A", "B", "C"),
  p_site = c(0.4, 0.3, 0.3),
  stringsAsFactors = FALSE
)
generate_bus_schedule(sched, frame, site = site, p_site = p_site, crew = 2)
#> # A tibble: 3 × 4
#>   site  p_site p_period inclusion_prob
#>   <chr>  <dbl>    <dbl>          <dbl>
#> 1 A        0.4        2            0.8
#> 2 B        0.3        2            0.6
#> 3 C        0.3        2            0.6