Hex Bin Layer¶

Population data aggregated into extruded hexagonal bins

The hex bin layer aggregates points into H3 hexagonal bins and extrudes each bin. You feed it HexBinPointDatum rows and shape the bins with accessors. Unlike the typed-field layers, several hex-bin accessors accept @frontend_python callbacks that run in the browser, so you can compute altitude, colour, and labels from each bin without writing JavaScript.

from IPython.display import display

from pyglobegl import (
    GlobeConfig,
    GlobeWidget,
    HexBinLayerConfig,
    HexBinPointDatum,
    frontend_python,
)


@frontend_python
def hex_altitude(hexbin):
    return hexbin["sumWeight"] * 0.01


@frontend_python
def point_weight(point):
    # point is an individual input row from hex_bin_points_data
    return point["weight"] * 2.0


@frontend_python
def hex_color(hexbin):
    return "#ff5500" if hexbin["sumWeight"] > 2 else "#66ccff"


@frontend_python
def hex_label(hexbin):
    return f"<b>{len(hexbin['points'])}</b> points in this hex bin"


points = [
    HexBinPointDatum(lat=0, lng=0, weight=1.0),
    HexBinPointDatum(lat=12, lng=15, weight=3.5),
]

config = GlobeConfig(
    hex_bin=HexBinLayerConfig(
        hex_bin_points_data=points,
        hex_bin_point_weight=point_weight,
        hex_altitude=hex_altitude,
        hex_top_color=hex_color,
        hex_side_color=hex_color,
        hex_label=hex_label,
    )
)

display(GlobeWidget(config=config))

Callback I/O¶

Frontend callback arguments are normalised to plain Python values (dict / list / str / float / bool / None) when they are JSON-serializable, so dict methods like .get(...) work inside callbacks such as hex_label.

Accessor	Argument	Returns
`hex_bin_point_lat(point)`	one row from `hex_bin_points_data`	`float`
`hex_bin_point_lng(point)`	one row from `hex_bin_points_data`	`float`
`hex_bin_point_weight(point)`	one row from `hex_bin_points_data`	`float`
`hex_top_color(hexbin)`	aggregated bin	CSS colour `str`
`hex_side_color(hexbin)`	aggregated bin	CSS colour `str`
`hex_altitude(hexbin)`	aggregated bin	non-negative `float` (globe-radius units)
`hex_label(hexbin)`	aggregated bin	HTML/text tooltip `str`

The hexbin argument has the shape:

{"h3Idx": str, "points": list[dict], "sumWeight": float}

Prefer defensive access

For compatibility across upstream changes, read bin fields defensively (for example hexbin.get("sumWeight", 0)) in case keys are missing or change shape.

hex_margin, hex_bin_point_lat, hex_bin_point_lng, and hex_bin_point_weight also accept @frontend_python callbacks when you need frontend-computed accessors.

From a GeoDataFrame

hexbin_points_from_gdf builds HexBinPointDatum rows from point geometries with a weight_column. See GeoPandas helpers.