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Build a polygon-to-polygon intersection table

Source: R/intersection.R
build_intersection.Rd

Computes every overlapping pair between a source polygon layer and a target polygon layer using a single vectorized sf::st_intersection() call, and returns one row per pair with area shares. Targets with no overlap at all receive one explicit all-NA-match row so every target feature is represented.

Usage

build_intersection(source, target, min_overlap = 0)

Arguments

source

An sf polygon layer (the matched unit).

target

An sf polygon layer (the index unit).

min_overlap

Numeric. Minimum intersection area in square metres for a pair to be retained. Defaults to 0, meaning strictly greater than zero (boundary-touching polygons that share only an edge are excluded).

Value

A tibble::tibble() with one row per overlapping pair (plus all-NA-match rows for unmatched targets). Fixed columns: interaction_id, target_id, target_name, target_source, source_id, source_name, source_source, relation, overlap_area_m2, share_of_target, share_of_source, match_distance_km, then every source attribute prefixed src_, every target attribute prefixed tgt_, then source_url_source, source_url_target, retrieved_at, simplify_used. No geometry column is ever emitted.

Examples

hive <- retrieve_hive()
cells <- hive[hive$Level == "Level 3", ][1:50, ]
build_intersection(cells, retrieve_phu_simple())
#> # A tibble: 81 × 27
#>    interaction_id target_id target_name      target_source source_id source_name
#>    <chr>          <chr>     <chr>            <chr>         <chr>     <chr>      
#>  1 2240__ND-457   2240      Chatham-Kent Pu… MOH Public H… ND-457    ND-457     
#>  2 2240__NE-457   2240      Chatham-Kent Pu… MOH Public H… NE-457    NE-457     
#>  3 2240__ND-456   2240      Chatham-Kent Pu… MOH Public H… ND-456    ND-456     
#>  4 2240__NE-456   2240      Chatham-Kent Pu… MOH Public H… NE-456    NE-456     
#>  5 2268__MU-461   2268      Windsor-Essex C… MOH Public H… MU-461    MU-461     
#>  6 2268__MV-461   2268      Windsor-Essex C… MOH Public H… MV-461    MV-461     
#>  7 2268__MV-460   2268      Windsor-Essex C… MOH Public H… MV-460    MV-460     
#>  8 2268__MW-460   2268      Windsor-Essex C… MOH Public H… MW-460    MW-460     
#>  9 2268__MX-460   2268      Windsor-Essex C… MOH Public H… MX-460    MX-460     
#> 10 2268__ML-459   2268      Windsor-Essex C… MOH Public H… ML-459    ML-459     
#> # ℹ 71 more rows
#> # ℹ 21 more variables: source_source <chr>, relation <chr>,
#> #   overlap_area_m2 <dbl>, share_of_target <dbl>, share_of_source <dbl>,
#> #   match_distance_km <dbl>, src_GRID_ID <chr>, src_Level <chr>,
#> #   src_HIVE_ID <int>, tgt_OGF_ID <int>, tgt_PHU_ID <int>,
#> #   tgt_PHU_NAME_ENG <chr>, tgt_PHU_NAME_FR <chr>,
#> #   tgt_GEOMETRY_UPDATE_DATETIME <dbl>, tgt_EFFECTIVE_DATETIME <dbl>, …