aboutsummaryrefslogtreecommitdiff
path: root/cluster.js
diff options
context:
space:
mode:
Diffstat (limited to 'cluster.js')
-rw-r--r--cluster.js64
1 files changed, 0 insertions, 64 deletions
diff --git a/cluster.js b/cluster.js
deleted file mode 100644
index c716063..0000000
--- a/cluster.js
+++ /dev/null
@@ -1,64 +0,0 @@
-const CheapRuler = require('cheap-ruler')
-const ruler = new CheapRuler(-37, 'meters')
-
-/**
- * Cluster points together where within threshold distance.
- *
- * @param {Array} features - GeoJSON Point Features
- * @param {number} thresholdDistance - Maximum distance between points to cluster together
- *
- * @returns {Array} clusters, where unclustered features are returned as single feature clusters
- */
-module.exports = (features, thresholdDistance) => {
- // Array of clusters where each cluster is a Set of feature index's
- const clusters = []
-
- features.map((a, ai) => {
- features.map((b, bi) => {
- // skip comparing with self
- if (ai === bi) return
-
- const distance = ruler.distance(a.geometry.coordinates, b.geometry.coordinates)
- if (distance < thresholdDistance) {
- // link into a cluster
- let addedToExistingCluster = false
- clusters.forEach((cluster, i) => {
- if (cluster.has(ai) || cluster.has(bi)) {
- // insert into this cluster
- clusters[i].add(ai)
- clusters[i].add(bi)
-
- addedToExistingCluster = true
- }
- })
-
- if (!addedToExistingCluster) {
- // create a new cluster
- const newCluster = new Set()
- newCluster.add(ai)
- newCluster.add(bi)
- clusters.push(newCluster)
- }
- } // else don't cluster together
- })
- })
-
- // result is array of clusters, including non-clustered features as single item clusters
- const result = clusters.map(cluster => {
- return Array.from(cluster).map(index => {
- return features[index]
- })
- })
-
- // find features not clustered
- features.map((feature, index) => {
- // if feature not a cluster, return as an single item cluster
- const featureInACluster = clusters.map(cluster => cluster.has(index)).reduce((acc, cur) => acc || !!cur, false)
- if (!featureInACluster) {
- result.push([feature])
- }
- })
-
- return result
-
-}