Calculate distance from a Point within a Polygon to its edge

Question

Let's say we have the following point and polygon:

poly = Polygon([(0, 0), (2,8), (14, 10), (6,1)])
point = Point(4,4)

Because point lies within poly, the distance from the first to the latter will be zero (poly.distance(point) will return 0.0).

Is there a way to instead calculate the distance to the nearest edge?

Note: Effectively the same question as this, but desire a solution in Python, ideally with Shapely.

score 20 · Accepted Answer · answered Jun 10 '17 at 06:34

20

Compare the point to the polygon's exterior ring:

poly.exterior.distance(point)

answered Jun 10 '17 at 06:34

sgillies

I'm working on a similar problem. What imports are needed to get Polygon and Point? – brad Sep 04 '19 at 14:20
4

@brad from shapely.geometry import Point, Polygon – Amstell Sep 09 '19 at 21:40
but this only works after we convert the coordinates to cartesian coordinates, isn't it? It won't work on Point(lat, lon) – Ciprian Tomoiagă May 05 '20 at 16:45

1 Answers1