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Expand admin shapes to one row per active year

Source: R/spatial.R
create_long_shape.Rd

Turns a shape table with year_start / year_end validity windows into a long table with one row per administrative unit per active year, spanning each unit's earliest start to the current year (a unit stays matchable in every year from its start; year_end does not close the span here), plus a 9999 sentinel year used to match records with an unknown year. When checks_dir is supplied, any administrative unit with more than one shape active in the same year is written to a CSV for manual review.

Usage

create_long_shape(data, level, checks_dir = NULL)

Arguments

data

An sf object (or data frame) carrying the admin name/GUID columns plus year_start and year_end.

level

Administrative level, "adm1" or "adm2". Determines the grouping columns.

checks_dir

Optional directory for the multiple-shape check CSV. When NULL (default) no check file is written.

Value

A tibble with the grouping columns plus active_year, year_start and year_end, one row per unit-year.

Examples

shapes <- tibble::tibble(
  adm0_guid = "g0", adm0 = "NIGERIA",
  adm1_guid = "g1", adm1 = "BORNO",
  year_start = 2018, year_end = 2020
)
create_long_shape(shapes, "adm1")
#> # A tibble: 10 × 7
#>    adm0_guid adm0    adm1  adm1_guid active_year year_start year_end
#>    <chr>     <chr>   <chr> <chr>           <int>      <dbl>    <dbl>
#>  1 g0        NIGERIA BORNO g1               2018       2018     2020
#>  2 g0        NIGERIA BORNO g1               2019       2018     2020
#>  3 g0        NIGERIA BORNO g1               2020       2018     2020
#>  4 g0        NIGERIA BORNO g1               2021       2018     2020
#>  5 g0        NIGERIA BORNO g1               2022       2018     2020
#>  6 g0        NIGERIA BORNO g1               2023       2018     2020
#>  7 g0        NIGERIA BORNO g1               2024       2018     2020
#>  8 g0        NIGERIA BORNO g1               2025       2018     2020
#>  9 g0        NIGERIA BORNO g1               2026       2018     2020
#> 10 g0        NIGERIA BORNO g1               9999       2018     2020