Points aren't properly parsed into H3 cells

[RaczeQ]

I was testing the library with different geometries, and I found out that points aren't properly matched to their H3 cells. I could filter out the points and parse them using official H3 bindings, but maybe there is an option to properly parse them in this library in a full package. I haven't tested the linestrings / multilinestrings and geometry collections yet.

from h3ronpy.pandas.vector import geometry_to_cells
from shapely.geometry import Point
import h3

# Manhattan Central Park
point = Point(-73.9575, 40.7938)

h3.int_to_str(geometry_to_cells(point, 8)[0])
# 8875588a83fffff - random cell near Null Island (0, 0)

h3.latlng_to_cell(point.y, point.x, 8)
# 882a1008d7fffff - proper cell

[nmandery]

Interesting - thank you for this report.

I just played around with this and was able to reproduce the issue with h3o directly, without h3ronpy being involved.

    #[test]
    fn central_park_point() {
        // Manhattan Central Park
        let pt = geo_types::Point::new(-73.9575, 40.7938);
        let cells: Vec<_> = h3o::geom::Geometry::from_degrees(geo_types::Geometry::Point(pt))
            .unwrap()
            .to_cells(Resolution::Eight)
            .collect();
        dbg!(LatLng::from(cells[0]));

        //  Using h3-py v3.7.x:
        //
        // $ python
        // Python 3.10.6 (main, May 29 2023, 11:10:38) [GCC 11.3.0] on linux
        // Type "help", "copyright", "credits" or "license" for more information.
        // >>> import h3.api.numpy_int as h3
        // >>> h3.geo_to_h3(40.7938, -73.9575, 8)
        // 613229523021856767

        assert_eq!(cells[0], CellIndex::try_from(613229523021856767).unwrap())
    }

output:

  Running unittests src/lib.rs (target/debug/deps/h3arrow-23df59f47b072b79)
[src/array/from_geo.rs:359] LatLng::from(cells[0]) = LatLng {
    lat_rad: 0.012440379887428356,
    lat_deg: 0.712781263089079,
    lng_rad: -0.022497083925138273,
    lng_deg: -1.288987960262031,
}


Left:  58-530425017777777 (8875588a83fffff)
Right: 21-020021537777777 (882a1008d7fffff)

thread 'array::from_geo::tests::central_park_point' panicked at 'assertion failed: `(left == right)`
  left: `58-530425017777777 (8875588a83fffff)`,
 right: `21-020021537777777 (882a1008d7fffff)`', src/array/from_geo.rs:360:9

@grim7reaper: Are you aware of any issues like this, or do you see anything I am messing up here?

[grim7reaper]

Yeah, mistake on my side.

When I changed the API to expose degrees by default (instead of radians, which is what H3 uses internally) I forgot to update a conversion method.

I've just released a version with the fix.

[nmandery]

Wow - you are fast ;)

I see you already released a patch version - @RaczeQ I will also release a bugfix-release soon.

[nmandery]

h3ronpy v0.17.4 with the fix is now on PyPI