Init from given files

examples/js/distances/distancePokerHands.js

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+/**
+ * The distance function that is specifically made for Poker Hands data set.
+ * The suit of the cards does not play an important role when finding
+ * the differences in poker hands so it was not used in calculations.
+ * @param  {node} source
+ * @param  {node} target
+ * @return {number}      the distance between source and target nodes.
+ */
+function calculateDistancePoker(source, target) {
+  var sumDiff = 0.0,
+      ordDiff = 1.0,
+      ORD_FACTOR = 1.5,
+      cards = ["C1", "C2", "C3", "C4", "C5"],
+      cols = 0;
+
+  // Iterate through cards
+  for (var i = 0; i < cards.length; i++) {
+    card = cards[i];
+    if (source.hasOwnProperty(card) && target.hasOwnProperty(card)) {
+      var s = parseInt(source[card]),
+          t = parseInt(target[card]);
+      // Calculate the squared difference.
+      sumDiff += (s-t) * (s-t);
+    }
+  }
+
+  // Class of poker hands describes the similarities the best
+  // so give it more priority than checking the differences between cards.
+  if (source.hasOwnProperty("CLASS") && target.hasOwnProperty("CLASS")) {
+    var s = parseInt(source["CLASS"]),
+        t = parseInt(target["CLASS"]);
+
+    // If classes differ, then scale them by a factor.
+    if (s !== t) {
+      ordDiff *= (ORD_FACTOR * (Math.abs(s-t)))
+    }
+  }
+
+  sumDiff = Math.sqrt(sumDiff);
+  sumDiff *= ordDiff;
+
+  return sumDiff;
+}