Build long-form crosswalk for a single primary geography — build_longform_for

For each feature of the primary geography, computes the intersection area with every feature of each target geography. Returns a tibble with one row per significant pairwise intersection, including area and percentage overlap.

Usage

build_longform_for_primary(
  all_gdf,
  primary_id,
  other_ids,
  buffer_feet = -50,
  min_area = 100,
  epsilon = 1e-06,
  max_primaries = NULL
)

Arguments

all_gdf: An sf object containing all boundaries, projected to EPSG:2263 (NY State Plane, feet).
primary_id: The geography ID to use as the primary (e.g., "cd").
other_ids: Character vector of target geography IDs.
buffer_feet: Negative buffer (in feet) applied during intersection to suppress edge artifacts. Default -50.
min_area: Minimum intersection area in square feet. Default 100.
epsilon: Tiny area threshold to suppress numerical noise. Default 1e-6.
max_primaries: Optional integer to limit the number of primary features processed (useful for testing).

Value

A tibble with columns primary_geo_id, primary_geo_name, other_geo_id, other_geo_name, primary_area_sqft, intersection_area_sqft, and pct_overlap.