alquist42/mapbox-play

app

Algo

export async function recommend (polygon, points, { threshold, scaleFactor, kmeansOptions, hullOptions }) {
  const ptsWithin = turf.pointsWithinPolygon(points, polygon)

  // Filter by score
  const filtered = ptsWithin.features.filter(feature => feature.properties.score >= threshold)

  if (filtered.length) {
    // Cluster K-means
    const clustered = turf.clustersKmeans(turf.featureCollection(filtered), kmeansOptions)

    // Concave hull from each cluster
    const villages = turf.clusterReduce(clustered, 'cluster', (previousValue, cluster) => {
      const hull = turf.concave(cluster, hullOptions)
      // scale down the polygon (raster buffer to prevent overlapping villages)
      return hull ? previousValue.concat([turf.transformScale(hull, scaleFactor)]) : previousValue
    }, [])

    return turf.featureCollection(villages)
  }

  return turf.featureCollection([])
}

Project setup

yarn install

Compiles and hot-reloads for development

yarn run serve

Compiles and minifies for production

yarn run build

Run your tests

yarn run test

Lints and fixes files

yarn run lint

Run your unit tests

yarn run test:unit

Customize configuration

See Configuration Reference.