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Dateline Chain Cluster

vectorGeoJSONPointEPSG:4326tinybundled

Three points within 50 km of each other across the antimeridian. Clustering that ignores longitude wrapping splits them into separate groups.

Point geometry of dateline_chain_cluster, rendered from the case's data
Point geometry, rendered from the case's actual geometry. Scale is normalized to the viewport and is not comparable between cases.
Property Value
Case ID dateline_chain_cluster
Category vector
Format GeoJSON
Geometry type Point
CRS EPSG:4326
Location Antimeridian, North Pacific — 179.80°E, 10.00°N → 179.80°W, 10.40°N (crosses the antimeridian — the box runs east from the first corner, over 180°)
Test tier unit
Size class tiny
Storage class bundled
Redistributable yes
Loader geopandas
Status validated

Use this case

import pytest


@pytest.mark.geocase_case("dateline_chain_cluster")
def test_dateline_chain_cluster(geocase_case) -> None:
    data = geocase_case.load()
    assert data is not None

Use GeoCase in your tests

Install the complete set of vector, raster, and NetCDF dependencies:

pip install "geocase[all]"

View GeoCase on PyPI.

What this case checks

Expose clustering logic that fails to connect a transitive dateline-spanning cluster when distances are measured in an unsuitable local projection.

Risk types covered

Expected behavior

Assertion Expected
expect_loadable yes
expect_valid_geometry yes
expect_crs yes
expected_epsg 4326
expected_geometry_types Point

Notes

This fixture places three points around the antimeridian. Geodesically they form one connected component under a 50 km threshold, but naive projected clustering can incorrectly split them into multiple clusters.

Required capabilities

  • load
  • geometry-validation
  • proximity-check

Files

Browse this case on GitHub

Source and license

  • Source: geocase-curated
  • License: MIT

Tags

clustering dateline point transitive_connectivity vector