Concave Hull

Generate concave hull for the given feature or Feature Collection.

Example

import json
from turfpy.transformation import concave
from geojson import FeatureCollection, Feature, Point
f1 = Feature(geometry=Point((-63.601226, 44.642643)))
f2 = Feature(geometry=Point((-63.591442, 44.651436)))
f3 = Feature(geometry=Point((-63.580799, 44.648749)))
f4 = Feature(geometry=Point((-63.573589, 44.641788)))
f5 = Feature(geometry=Point((-63.587665, 44.64533)))
f6 = Feature(geometry=Point((-63.595218, 44.64765)))
fc = [f1, f2, f3, f4, f5, f6]
ch = concave(FeatureCollection(fc), alpha=100)
print(json.dumps(ch, indent=2, sort_keys=True))

{
  "geometry": {
    "coordinates": [
      [
        [
          -63.587665,
          44.64533
        ],
        [
          -63.601226,
          44.642643
        ],
        [
          -63.595218,
          44.64765
        ],
        [
          -63.591442,
          44.651436
        ],
        [
          -63.580799,
          44.648749
        ],
        [
          -63.573589,
          44.641788
        ],
        [
          -63.587665,
          44.64533
        ]
      ]
    ],
    "type": "Polygon"
  },
  "properties": {},
  "type": "Feature"
}

Interactive Example

from geojson import FeatureCollection, Feature, Point
from ipyleaflet import Map, GeoJSON
from turfpy.transformation import concave

f1 = Feature(geometry=Point((-63.601226, 44.642643)))
f2 = Feature(geometry=Point((-63.591442, 44.651436)))
f3 = Feature(geometry=Point((-63.580799, 44.648749)))
f4 = Feature(geometry=Point((-63.573589, 44.641788)))
f5 = Feature(geometry=Point((-63.587665, 44.64533)))
f6 = Feature(geometry=Point((-63.595218, 44.64765)))
fc = [f1, f2, f3, f4, f5, f6]
fc = FeatureCollection(fc)

geo_json = GeoJSON(data=fc)

spline_geo_json = GeoJSON(data=concave(FeatureCollection(fc), alpha=100), style={'color': 'red'})

m = Map(center=[44.64740465397292, -63.58361206948757], zoom=14)

m.add_layer(geo_json)
m.add_layer(spline_geo_json)

m