Change the Live Test multi-label classification

I've changed way in which the "Live Test" tool selects the categories.
The previous method was ad hoc and didn't produce good results in
general. For the one version, I decided to implement the K-Means
algorithm to divide the categories into two clusters, one for
"select as classified" and another for "ignore". The key idea is to
partitioned the categories according to the obtained confidence value.

pyss3/resources/visual_classifier/js/app.js

@@ -186,8 +186,7 @@ app.controller("mainCtrl", function($scope) {
   }
 
   $scope.is_cat_active = function (cat_info) {
-    return ($scope.ss3.cvns[0][2] < 1 && cat_info[2] >= .75) ||
-           ($scope.ss3.cvns[0][2] > 1 && cat_info[1] >= .35 && cat_info[2] > 1);
+    return active_cats.indexOf(cat_info[0]) != -1;
   }
 
   $scope.need_space = function(words, i, sents, j){
@@ -234,16 +233,11 @@ app.controller("mainCtrl", function($scope) {
           $scope.ss3 = data;
           $scope.scat = -1;
           active_cats = [];
-          for (var i in data.cvns){
-            var cvn = data.cvns[i];
-            if (cvn[1] >= .35 && cvn[2] > 1){
-              active_cats.push(cvn[0]);
-            }
-          }
-          if (active_cats.length < 2){
-            if (active_cats.length == 0)
-              active_cats.push(data.cvns[0][0]);
+          if (data.cvns.length == 2){
+            active_cats.push(data.cvns[0][0]);
             active_cats.push(data.cvns[1][0]);
+          }else{
+            active_cats = __k_means_active_cat__(data.cvns);
           }
           __create_chart_values__();
 
@@ -269,6 +263,32 @@ app.controller("mainCtrl", function($scope) {
     );
   }
 
+  function __k_means_active_cat__(cats){
+    var cent = {neg: -1, pos: -1};  // centroids (one for each "group")
+    var clust = {neg: [], pos: []};  // clusters (one for each "group")
+    var new_cent_neg = cats[cats.length - 1][2];
+    var new_cent_pos = cats[0][2];
+    var active_cats = null;
+    while (cent.pos != new_cent_pos || cent.neg != new_cent_neg){
+      cent.neg = new_cent_neg;
+      cent.pos = new_cent_pos;
+      clust.neg = []; clust.pos = [];
+      active_cats = [];
+      for (var i=0, cat_cv; i < cats.length; i++){
+        cat_cv = cats[i][2];
+        if (Math.abs(cent.neg - cat_cv) < Math.abs(cent.pos - cat_cv)){
+          clust.neg.push(cat_cv);
+        }else{
+          clust.pos.push(cat_cv);
+          active_cats.push(cats[i][0]);
+        }
+      }
+      new_cent_neg = clust.neg.reduce((a,b) => a + b, 0) / clust.neg.length;
+      new_cent_pos = clust.pos.reduce((a,b) => a + b, 0) / clust.pos.length;
+    }
+    return active_cats;
+  }
+
   function __create_chart_values__(){
     var $ss3 = $scope.ss3;
     var $chart = $scope.chart;