Add ocean.json and test, which is currently failing

[alexgleith]

Related issues and pull requests

Description

Bounding box function is failing on a complex global geometry that does not overlap the antimeridian.

Checklist

• Add tests
• Add docs
• Update CHANGELOG

[gadomski]

@alexgleith the ocean.json that you provided seemed broken to me — it was a multipolygon with only one member, and the exterior shape looked like it was a second element of the polygon, not the first. I corrected it and the tests pass. Can you check my updated ocean.json (cdc7172) and tell me if I'm missing something?

[alexgleith]

Oh damn, sorry.

I was using this data file, but it's a FeatureCollection, which isn't supported, so I attempted to manually make it a multipolygon and clearly failed.

https://github.com/opendatacube/odc-geo/blob/develop/odc/geo/data/ocean.geojson.xz

Creating a BBOX for that Ocean poly resulted in a small slice about the width of the Black Sea, which is the issue I was hoping to highlight.

[gadomski]

Yeah, I think that ocean file is bad too. I extracted the shape with:

jq '.features[0].geometry' ~/Downloads/ocean.geojson > tests/data/output/ocean.json

Then visualized it with shapely:

import shapely.geometry
import json

with open("tests/data/output/ocean.json") as f:
    shape = json.load(f)
shapely.geometry.shape(shape)

[alexgleith]

What's wrong with it?

It works in geopandas and QGIS.

[gadomski]

What's wrong with it?

Ah, nevermind, I messed up. The source file is fine, it's just a FeatureCollection with two features. When you made your multi-polygon, you put the first feature first, which is the Baltic Sea. If you grab the second feature, tests are fine:

jq '.features[1].geometry' ~/Downloads/ocean.geojson > tests/data/output/ocean.json

[alexgleith]

Do you think the bbox should return a bbox of both, or should I be doing that somewhere else?

Currently it returns the X bounds for just the Baltic, and the Y bounds for the whole ocean, I think.

[gadomski]

🤔 not sure I agree:

$ jq '.features[0].geometry' ~/Downloads/ocean.geojson | antimeridian bbox  # the first feature is the Baltic
[46.6821, 36.7005, 54.7369, 47.0487]
$ jq '.features[1].geometry' ~/Downloads/ocean.geojson | antimeridian bbox  # the second feature is the whole oceaen
[-180.0, -85.609, 180.0, 90.0]

NB I'm using the as-of-yet unreleased bbox subcommand for the CLI, added here: #148

[alexgleith]

Oh, I see... That's my facepalm!

from odc.geo.data import ocean_geom
from antimeridian import bbox

ocean = ocean_geom()
bbox = bbox(ocean)
bbox

[46.6821, -85.609, 54.7369, 90.0]

I expected the bbox of everything, but instead got the bbox of the first feature.

We can close this then, bbox should really be working per-feature and doing a bbox of a whole set of features is someone else's problem!

[alexgleith]

Also: bbox(ocean.convex_hull) is correct, which is much simpler!

Thanks for your patience, Pete!

[gadomski]

Of course, no problem at all! Thanks for kicking the tires.