code: protected double decisionFunction(int v)
      {
          double sum = 0;
          for(int i = 0; i < vecs.size(); i++)
              if(alphas[i] > 0)
                  sum += alphas[i] * label[i] * kEval(v, i);
  
          return sum;
      }
docs: Returns the local decision function for classification training purposes
  without the bias term
  @param v the index of the point to select
  @return the decision function output sans bias