GitHub - mmadfox/go-geojson2h3: Conversion utilities between H3 indexes and GeoJSON (original) (raw)

go-geojson2h3

The geojson2h3 library includes a set of utilities for conversion between GeoJSON Objects:

Point, MultiPoint,
LineString, MultiLineString
Polygon,MultiPolygon
GeometryCollection
Feature,FeatureCollection
Circle

and H3 hexagon indexes, using:H3-GO andGeoJSON

Installation

$ go get github.com/mmadfox/go-geojson2h3

API

// ToH3 converts a GeoJSON objects to a list of hexagons with specified resolution. ToH3(resolution int, o geojson.Object) (indexes []h3.H3Index, err error)

// ToFeatureCollection converts a set of hexagons to a GeoJSON FeatureCollection // with the set outline(s). The feature's geometry type will be Polygon. ToFeatureCollection(indexes []h3.H3Index) (*geojson.FeatureCollection, error)

Examples

package main

import ( "fmt"

"github.com/mmadfox/go-geojson2h3"
"github.com/tidwall/geojson"
"github.com/uber/h3-go/v3"

)

func main() { resolution := 9 object, err := geojson.Parse({"type":"FeatureCollection","features":[{"type":"Feature","properties":{"shape":"Polygon","name":"Unnamed Layer","category":"default"},"geometry":{"type":"Polygon","coordinates":[[[-73.901303,40.756892],[-73.893924,40.743755],[-73.871476,40.756278],[-73.863378,40.764175],[-73.871444,40.768467],[-73.879852,40.760014],[-73.885515,40.764045],[-73.891522,40.761054],[-73.901303,40.756892]]]},"id":"a6ca1b7e-9ddf-4425-ad07-8a895f7d6ccf"}]}, nil) if err != nil { panic(err) }

indexes, err := geojson2h3.ToH3(resolution, object)
if err != nil {
    panic(err)
}
for _, index := range indexes {
    fmt.Printf("h3index: %s\n", h3.ToString(index))
}

featureCollection, err := geojson2h3.ToFeatureCollection(indexes)
if err != nil {
    panic(err)
}
fmt.Println("Polyfill:")
fmt.Println(featureCollection.JSON())

}

Contributing

Pull requests and Github issues are welcome. Please include tests for new work, and keep the library test coverage at 90-100%.