Fix shapes that cross the antimeridian. See the documentation for information about the underlying algorithm. Depends on shapely and numpy.

Can fix:

• Shapely Polygon, MultiPolygon, LineString, and MultiLineString objects
• GeoJSON Polygons, MultiPolygons, Features and FeatureCollections, as dictionaries
• Anything that has a __geo_interface__

python -m pip install antimeridian

Then:

import antimeridian

fixed = antimeridian.fix_geojson(geojson)

We also have some utilities to create bounding boxes and centroids from antimeridian-crossing polygons and multipolygons. See the documentation for a complete API reference.

Use the cli optional dependency to install the antimeridian CLI:

python -m pip install 'antimeridian[cli]'
antimeridian fix input.json > output.json

Get uv. Then:

git clone https://github.com/gadomski/antimeridian
cd antimeridian
uv sync

We use pytest for tests:

uv run pytest

We use Sphinx for docs:

make -C docs html

See CONTRIBUTING.md.

Apache-2.0