Coverage audit: which force-months exist, and can be compared

lamp_coverage() returns the force by month by file-type grid behind a panel or a records table, with one status per cell (submitted, missing, not_read, refreshed, partial_suspected), the record count, the archive version used, any changelog note, and a mismatch flag for months where a stop-and-search file exists without a street file or the reverse. Its plot() method draws the grid as a heat map.

Usage

lamp_coverage(x, changelog = NULL)

lamp_coverage_compare(coverage, period_a, period_b, file_type = "street")

Arguments

x: A lamp_panel from lamp_panel() or records from lamp_read_crime(), lamp_read_outcomes() or lamp_read_stop_counts().
changelog: Optional lamp_changelog() table; entries saying a force re-supplied months mark those months refreshed.
coverage: A lamp_coverage table.
period_a, period_b: Two periods, each a length-two vector of months ("YYYY-MM" or Dates) giving the first and last month inclusive.
file_type: Which file type to compare (default "street").

Value

lamp_coverage() returns a tibble of class lamp_coverage with columns force_id, month, file_type, status, n_records, archive, n_versions, versions_differ, note and mismatch.

lamp_coverage_compare() returns a tibble with one row per force: n_months_a, n_usable_a, n_months_b, n_usable_b (months with status submitted or refreshed), n_partial_a, n_partial_b, n_refreshed_a, n_refreshed_b, n_mismatch_a, n_mismatch_b and comparable (TRUE when every month in both periods is submitted, with no mismatch).

Details

lamp_coverage_compare() summarises comparability per force between two periods: the share of months with usable files, and whether every month in both periods was submitted without refreshes, partial submissions or mismatches.

Examples

panel <- lamp_sample_panel()
cov <- lamp_coverage(panel)
cov
#> streetlamp coverage: 2 forces, 2 file types, 16 mismatched force-months.
#> # A tibble: 96 × 10
#>    force_id    month      file_type       status    n_records archive n_versions
#>    <chr>       <date>     <chr>           <chr>         <int> <chr>        <int>
#>  1 dyfed-powys 2024-08-01 stop-and-search submitted       279 2026-07          2
#>  2 dyfed-powys 2024-09-01 stop-and-search submitted       280 2026-07          2
#>  3 dyfed-powys 2024-10-01 stop-and-search submitted       355 2026-07          2
#>  4 dyfed-powys 2024-11-01 stop-and-search submitted       320 2026-07          2
#>  5 dyfed-powys 2024-12-01 stop-and-search submitted       221 2026-07          2
#>  6 dyfed-powys 2025-01-01 stop-and-search submitted       270 2026-07          2
#>  7 dyfed-powys 2025-02-01 stop-and-search submitted       271 2026-07          2
#>  8 dyfed-powys 2025-03-01 stop-and-search submitted       315 2026-07          2
#>  9 dyfed-powys 2025-04-01 stop-and-search submitted       273 2026-07          2
#> 10 dyfed-powys 2025-05-01 stop-and-search submitted       275 2026-07          2
#> # ℹ 86 more rows
#> # ℹ 3 more variables: versions_differ <lgl>, note <chr>, mismatch <lgl>
table(cov$file_type, cov$status)
#>                  
#>                   missing submitted
#>   stop-and-search       8        40
#>   street                0        48
# Dyfed-Powys stopped submitting stop-and-search files in December 2025
cov[cov$mismatch %in% TRUE, c("force_id", "month", "file_type", "status")]
#> Warning: Unknown or uninitialised column: `mismatch`.
#> streetlamp coverage: 1 force, 2 file types, 0 mismatched force-months.
#> # A tibble: 16 × 4
#>    force_id    month      file_type       status   
#>    <chr>       <date>     <chr>           <chr>    
#>  1 dyfed-powys 2025-12-01 stop-and-search missing  
#>  2 dyfed-powys 2026-01-01 stop-and-search missing  
#>  3 dyfed-powys 2026-02-01 stop-and-search missing  
#>  4 dyfed-powys 2026-03-01 stop-and-search missing  
#>  5 dyfed-powys 2026-04-01 stop-and-search missing  
#>  6 dyfed-powys 2026-05-01 stop-and-search missing  
#>  7 dyfed-powys 2026-06-01 stop-and-search missing  
#>  8 dyfed-powys 2026-07-01 stop-and-search missing  
#>  9 dyfed-powys 2025-12-01 street          submitted
#> 10 dyfed-powys 2026-01-01 street          submitted
#> 11 dyfed-powys 2026-02-01 street          submitted
#> 12 dyfed-powys 2026-03-01 street          submitted
#> 13 dyfed-powys 2026-04-01 street          submitted
#> 14 dyfed-powys 2026-05-01 street          submitted
#> 15 dyfed-powys 2026-06-01 street          submitted
#> 16 dyfed-powys 2026-07-01 street          submitted
lamp_coverage_compare(cov, c("2024-08", "2025-07"), c("2025-08", "2026-07"),
  file_type = "stop-and-search"
)
#> # A tibble: 2 × 12
#>   force_id   n_months_a n_usable_a n_months_b n_usable_b n_partial_a n_partial_b
#>   <chr>           <int>      <int>      <int>      <int>       <int>       <int>
#> 1 dyfed-pow…         12         12         12          4           0           0
#> 2 west-york…         12         12         12         12           0           0
#> # ℹ 5 more variables: n_refreshed_a <int>, n_refreshed_b <int>,
#> #   n_mismatch_a <int>, n_mismatch_b <int>, comparable <lgl>