code: public double score(int[] featureVector, int currentTag)
      {
          double score = 0;
          for (int index : featureVector)
          {
              if (index == -1)
              {
                  continue;
              }
              else if (index < -1 || index >= featureMap.size())
              {
                  throw new IllegalArgumentException("在打分时传入了非法的下标");
              }
              else
              {
                  index = index * featureMap.tagSet.size() + currentTag;
                  score += parameter[index];    // 其实就是特征权重的累加
              }
          }
          return score;
      }
docs: 通过命中的特征函数计算得分
  
  @param featureVector 压缩形式的特征id构成的特征向量
  @return