Shinobi CE officially lands on Gitlab

web/libs/js/clusterPoints.js

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+// Original is by Nathan Epstein and found at https://github.com/NathanEpstein/clusters/blob/master/clusters.js
+// Modified for browser
+
+var Cluster = {
+
+  data: getterSetter([], function(arrayOfArrays) {
+      if(!arrayOfArrays[0]){
+          arrayOfArrays[0]=[0,0]
+      }
+    var n = arrayOfArrays[0].length;
+    return (arrayOfArrays.map(function(array) {
+      return array.length == n;
+    }).reduce(function(boolA, boolB) { return (boolA & boolB) }, true));
+  }),
+
+  clusters: function() {
+    var pointsAndCentroids = kmeans(this.data(), {k: this.k(), iterations: this.iterations() });
+    var points = pointsAndCentroids.points;
+    var centroids = pointsAndCentroids.centroids;
+
+    return centroids.map(function(centroid) {
+      return {
+        centroid: centroid.location(),
+        points: points.filter(function(point) { return point.label() == centroid.label() }).map(function(point) { return point.location() }),
+      };
+    });
+  },
+
+  k: getterSetter(undefined, function(value) { return ((value % 1 == 0) & (value > 0)) }),
+
+  iterations: getterSetter(Math.pow(10, 3), function(value) { return ((value % 1 == 0) & (value > 0)) }),
+
+};
+
+function kmeans(data, config) {
+  // default k
+  var k = config.k || Math.round(Math.sqrt(data.length / 2));
+  var iterations = config.iterations;
+
+  // initialize point objects with data
+  var points = data.map(function(vector) { return new Point(vector) });
+
+  // intialize centroids randomly
+  var centroids = [];
+  for (var i = 0; i < k; i++) {
+    centroids.push(new Centroid(points[i % points.length].location(), i));
+  };
+
+  // update labels and centroid locations until convergence
+  for (var iter = 0; iter < iterations; iter++) {
+    points.forEach(function(point) { point.updateLabel(centroids) });
+    centroids.forEach(function(centroid) { centroid.updateLocation(points) });
+  };
+
+  // return points and centroids
+  return {
+    points: points,
+    centroids: centroids
+  };
+
+};
+
+// objects
+function Point(location) {
+  var self = this;
+  this.location = getterSetter(location);
+  this.label = getterSetter();
+  this.updateLabel = function(centroids) {
+    var distancesSquared = centroids.map(function(centroid) {
+      return sumOfSquareDiffs(self.location(), centroid.location());
+    });
+    self.label(mindex(distancesSquared));
+  };
+};
+
+function Centroid(initialLocation, label) {
+  var self = this;
+  this.location = getterSetter(initialLocation);
+  this.label = getterSetter(label);
+  this.updateLocation = function(points) {
+    var pointsWithThisCentroid = points.filter(function(point) { return point.label() == self.label() });
+    if (pointsWithThisCentroid.length > 0) self.location(averageLocation(pointsWithThisCentroid));
+  };
+};
+
+// convenience functions
+function getterSetter(initialValue, validator) {
+  var thingToGetSet = initialValue;
+  var isValid = validator || function(val) { return true };
+  return function(newValue) {
+    if (typeof newValue === 'undefined') return thingToGetSet;
+    if (isValid(newValue)) thingToGetSet = newValue;
+  };
+};
+
+function sumOfSquareDiffs(oneVector, anotherVector) {
+  var squareDiffs = oneVector.map(function(component, i) {
+    return Math.pow(component - anotherVector[i], 2);
+  });
+  return squareDiffs.reduce(function(a, b) { return a + b }, 0);
+};
+
+function mindex(array) {
+  var min = array.reduce(function(a, b) {
+    return Math.min(a, b);
+  });
+  return array.indexOf(min);
+};
+
+function sumVectors(a, b) {
+  return a.map(function(val, i) { return val + b[i] });
+};
+
+function averageLocation(points) {
+  var zeroVector = points[0].location().map(function() { return 0 });
+  var locations = points.map(function(point) { return point.location() });
+  var vectorSum = locations.reduce(function(a, b) { return sumVectors(a, b) }, zeroVector);
+  return vectorSum.map(function(val) { return val / points.length });
+};