Tutorial

Assign a fresh hierarchical code to a flat, uncoded layer, then reconcile it against a new delivery of the same boundary.

Assign a fresh code¶

code-create ranks each level's units under their parent and assigns a fresh sequential code in a chosen format:

topo-tools code-create admin2.geojson admin2_coded.geojson \
  --root-code AFG --delimiter . --min-width 3

Reconcile against a new delivery¶

code-update classifies every unit of an uncoded NEW layer against the already-coded OLD one (the same engine change uses), then retains, replaces, or retires each code per that classification, cascading a changed parent's new code prefix down to its unchanged/renamed descendants. Format is auto-detected off OLD's own codes:

topo-tools code-update admin2_coded.geojson admin2_new.geojson

Add --link-by-code (plus --code-column-a/--code-column-b) if both layers share a separate stable source identifier, to link a relocated unit that spatial overlap alone would misclassify.

See the code-create and code-update references, and the code explanation, for the code format and retention policy.