Client version

knear-client.js

@@ -0,0 +1,82 @@
+var kNear = function(k) {
+    //PRIVATE
+    var training = [];
+
+
+    //compute the euclidean distance between two vectors
+    //function assumes vectors are arrays of equal length
+    var dist = function(v1, v2) {
+        var sum = 0;
+        v1.forEach(function(val, index) {
+            sum += Math.pow(val - v2[index], 2);
+        });
+        return Math.sqrt(sum);
+    };
+
+    var updateMax = function(val, arr) {
+        var max = 0;
+        arr.forEach(function(obj) {
+            max = Math.max(max, obj.d);
+        });
+        return max;
+    };
+
+    function mode(store) {
+        var frequency = {}; // array of frequency.
+        var max = 0; // holds the max frequency.
+        var result; // holds the max frequency element.
+        for (var v in store) {
+            frequency[store[v]] = (frequency[store[v]] || 0) + 1; // increment frequency.
+            if (frequency[store[v]] > max) { // is this frequency > max so far ?
+                max = frequency[store[v]]; // update max.
+                result = store[v]; // update result.
+            }
+        }
+        return result;
+    }
+
+
+    //PUBLIC
+
+    //add a point to the training set
+    this.learn = function(vector, label) {
+        var obj = { v: vector, lab: label };
+        training.push(obj);
+    };
+
+    this.classify = function(v) {
+        var voteBloc = [];
+        var maxD = 0;
+        training.forEach(function(obj) {
+            var o = { d: dist(v, obj.v), vote: obj.lab };
+            if (voteBloc.length < k) {
+                voteBloc.push(o);
+                maxD = updateMax(maxD, voteBloc);
+            } else {
+                if (o.d < maxD) {
+                    var bool = true;
+                    var count = 0;
+                    while (bool) {
+                        if (Number(voteBloc[count].d) === maxD) {
+                            voteBloc.splice(count, 1, o);
+                            maxD = updateMax(maxD, voteBloc);
+                            bool = false;
+                        } else {
+                            if (count < voteBloc.length - 1) {
+                                count++;
+                            } else {
+                                bool = false;
+                            }
+                        }
+                    }
+                }
+            }
+
+        });
+        var votes = [];
+        voteBloc.forEach(function(el) {
+            votes.push(el.vote);
+        });
+        return mode(votes);
+    };
+};