Comparison with WRAPDATELINE¶

GDAL has the WRAPDATELINE option to deal with geometries that cross the antimeridian, which was added to ogr2ogr in v1.7.0 via the -wrapdateline flag. As demonstrated below, antimeridian has more-or-less the same behavior but includes a couple of modifications and improvements:

• antimeridian outputs the same geometry type as the input. ogr2ogr outputs a FeatureCollection.
• ogr2ogr requires tuning via the -datelineoffset flag. To get corrected outputs from ogr2ogr, we had to set the -datelineoffset to 180 (the default is 10).
• antimeridian handles the poles (usually).

In [ ]:

import json
import subprocess

import shapely.geometry
from cartopy.crs import PlateCarree
from matplotlib import pyplot


def plot(name: str) -> None:
    path = f"../tests/data/input/{name}.json"
    antimeridian_output = shapely.geometry.shape(
        json.loads(subprocess.check_output(["antimeridian", "fix", path]))
    )
    ogr2ogr_feature_collection = json.loads(
        subprocess.check_output(
            [
                "ogr2ogr",
                "-q",
                "-f",
                "GeoJSON",
                "-wrapdateline",
                "-datelineoffset",
                "180",
                "/vsistdout/",
                path,
            ],
        )
    )
    assert len(ogr2ogr_feature_collection["features"]) == 1
    ogr2ogr_output = shapely.geometry.shape(
        ogr2ogr_feature_collection["features"][0]["geometry"]
    )

    figure = pyplot.figure()

    axes = figure.add_subplot(121, projection=PlateCarree())
    axes.set_title(f"{name} (antimeridian)")
    axes.stock_img()
    axes.coastlines()
    axes.add_geometries(
        antimeridian_output, crs=PlateCarree(), color="coral", alpha=0.7
    )

    axes = figure.add_subplot(122, projection=PlateCarree())
    axes.set_title(f"{name} (ogr2ogr)")
    axes.stock_img()
    axes.coastlines()
    axes.add_geometries(ogr2ogr_output, crs=PlateCarree(), color="coral", alpha=0.7)


for name in [
    "split",
    "multi-split",
    "complex-split",
    "two-holes",
    "line",
    "issues-124",
]:
    plot(name)

import json import subprocess import shapely.geometry from cartopy.crs import PlateCarree from matplotlib import pyplot def plot(name: str) -> None: path = f"../tests/data/input/{name}.json" antimeridian_output = shapely.geometry.shape( json.loads(subprocess.check_output(["antimeridian", "fix", path])) ) ogr2ogr_feature_collection = json.loads( subprocess.check_output( [ "ogr2ogr", "-q", "-f", "GeoJSON", "-wrapdateline", "-datelineoffset", "180", "/vsistdout/", path, ], ) ) assert len(ogr2ogr_feature_collection["features"]) == 1 ogr2ogr_output = shapely.geometry.shape( ogr2ogr_feature_collection["features"][0]["geometry"] ) figure = pyplot.figure() axes = figure.add_subplot(121, projection=PlateCarree()) axes.set_title(f"{name} (antimeridian)") axes.stock_img() axes.coastlines() axes.add_geometries( antimeridian_output, crs=PlateCarree(), color="coral", alpha=0.7 ) axes = figure.add_subplot(122, projection=PlateCarree()) axes.set_title(f"{name} (ogr2ogr)") axes.stock_img() axes.coastlines() axes.add_geometries(ogr2ogr_output, crs=PlateCarree(), color="coral", alpha=0.7) for name in [ "split", "multi-split", "complex-split", "two-holes", "line", "issues-124", ]: plot(name)

ERROR 1: TopologyException: side location conflict at 234.90917500381769 14.76580303507545. This can occur if the input geometry is invalid.
ERROR 1: TopologyException: side location conflict at 234.90917500381769 14.76580303507545. This can occur if the input geometry is invalid.