float Choose (float[] probs) {

         float total = 0;

         foreach (float elem in probs) {
             total += elem;
         }

         float randomPoint = Random.value * total;

         for (int i= 0; i < probs.Length; i++) {
             if (randomPoint < probs[i]) {
                 return i;
             }
             else {
                 randomPoint -= probs[i];
             }
         }
         return probs.Length - 1;
     }