code: private int reduceNondominatedSet(double[][] front, int noPoints, int objective,
                                      double threshold) {
      int n;
      int i;
  
      n = noPoints;
      for (i = 0; i < n; i++) {
        if (front[i][objective] <= threshold) {
          n--;
          swap(front, i, n);
        }
      }
  
      return n;
    }
docs: /* remove all points which have a value <= 'threshold' regarding the
  dimension 'objective'; the points referenced by
  'front[0..noPoints-1]' are considered; 'front' is resorted, such that
  'front[0..n-1]' contains the remaining points; 'n' is returned