Refactor: Extract functions

src/interpolation/helpers.js

@@ -0,0 +1,48 @@
+export function takeSampleFrom(nodes, amount) {
+  let randElements = [],
+      max = nodes.length;
+
+  for (var i = 0; i < amount; ++i) {
+    var rand = nodes[Math.floor((Math.random() * max))];
+    // If the rand is already in random list or in exclude list
+    // ignore it and get a new value.
+    while (randElements.includes(rand)) {
+      rand = nodes[Math.floor((Math.random() * max))];
+    }
+    randElements.push(rand);
+  }
+  var remainder = nodes.filter(function (node) {
+    return !randElements.includes(node);
+  });
+
+  return {
+    sample: randElements,
+    remainder: remainder
+  };
+}
+
+// With a circle radius r, and center at (h,k),
+// Find the coordinate of a point at angle degree
+export function pointOnCircle(h, k, angle, r) {
+  let x = h + r*Math.cos(toRadians(angle));
+  let y = k + r*Math.sin(toRadians(angle));
+
+  return {
+    x: x,
+    y: y
+  };
+}
+
+function toRadians(degrees) {
+  return degrees * (Math.PI / 180);
+}
+
+export function sumDistError(node, samples, realDistances) {
+  let total = 0.0;
+  for (let i = 0; i < samples.length; i++) {
+    let sample = samples[i];
+    let lowDDistance = Math.hypot(sample.x - node.x, sample.y - node.y);
+    total += Math.abs(lowDDistance - realDistances[i]);
+  }
+  return total;
+}