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Diagnose ethnicity composition in daylight and darkness

Source: R/infer-veil.R
sl_veil_of_darkness.Rd

Excludes every force-month that fails or lacks the contract's time-quality screen, retaining an explicit exclusion table. Annual evening clock-time bounds use each distinct location and year. Civil darkness begins at dusk; ambiguous sunset-to-dusk observations are excluded. Times and clock changes use Europe/London, including British summer time. The logistic comparison controls clock time (natural spline), weekday, month and force where these vary. The DST option further restricts to weeks around both clock changes and adds transition and running-day controls; it is a local darkness comparison. The method was developed for vehicle stops. Transfer to pedestrian searches requires assumptions about visibility, activity, deployment and selection.

Usage

sl_veil_of_darkness(
  records,
  boundaries = NULL,
  twilight = c("civil", "sunset"),
  window = "intertwilight",
  design = c("intertwilight", "dst"),
  reference = "White",
  comparison = "Black",
  dst_weeks = 3,
  conf_level = 0.95
)

Arguments

records

Contract-bearing search records.

boundaries

Optional sf study region; restrict published points to it. Missing locations are never replaced by centroids.

twilight

Civil twilight end or sunset definition of darkness.

window

Currently only intertwilight, the annual evening overlap window.

design

Annual intertwilight or local DST-window comparison.

reference, comparison

Known self-defined ethnicity groups.

dst_weeks

Weeks on either side of each clock change for the DST design.

conf_level

Logistic Wald confidence level.

Value

An sl_veil tibble with an odds ratio, interval and fit status. Attributes steps, excluded_force_months, assumptions, data and model retain the full design audit. A gated or unidentifiable sample has an undefined ratio.

See also

sl_timestamp_quality(), sl_hit_rates()

Other inference: sl_count_model(), sl_hit_rates(), sl_simulate(), sl_spatial_disparity(), sl_spatial_map()

Examples

# Date-only records are explicitly refused by the time-quality screen.
x <- sl_sample()[1:10, ]
day <- as.Date(x$date, tz = "Europe/London")
x$date <- as.POSIXct(paste(day, "00:00:00"), tz = "Europe/London")
x$date_raw <- format(x$date, "%Y-%m-%dT%H:%M:%S%z")
attr(x, "contract")$timestamps <- sl_timestamp_quality(x)
sl_veil_of_darkness(x)
#> Excluded 1 unreliable force-month(s).
#> # A tibble: 1 × 14
#>   term  odds_ratio conf_low conf_high log_std_error     n status  model_warnings
#>   <chr>      <dbl>    <dbl>     <dbl>         <dbl> <int> <chr>   <chr>         
#> 1 dark          NA       NA        NA            NA     0 insuff… ""            
#> # ℹ 6 more variables: reference <chr>, comparison <chr>, design <chr>,
#> #   twilight <chr>, dark_stops <int>, daylight_stops <int>