polygon-similarity

> quick comparison of polygons using rasterization

advantages

- optimized for speed
- result is a score between 0 and 1
- no configuration required
- predictable linear run-time

score

The score is basically a modified Jaccard similarity coefficient.
The geometries are converted to an in-memory raster representation using the dufour-peyton-intersection algorithm.
Pixels that fall within a geometry are represented as 1 and
pixels that fall outside are represented as 0.
We count all the pixels that have a value of 1 for both bands and divide that
by the total number of pixels that have a value of 1 for at least one of the bands.

usage

``js
import { compare } from "polygon-similarity";

const a = { "type": "Polygon", "coordinates": [[[30,10],[40,40],[20,40],[10,20],[30,10]]] };

const b = { "type": "Polygon", "coordinates": [[[29.93,10.49],[40.44,39.76],[20.39,40.31],[10.45,20.20],[29.93,10.49]]] };

compare(a, b);
{
// modified Jaccard similarity coefficient
"score": 0.9565577847786437,

"counts": {
"0:0": 3969, // both outside
"1:1": 5769, // both inside
"1:0": 179, // only first inside
"0:1": 83 // only second inside
}
}
``