Because of this feature the symptom dimension of chronic gastritis is hard to be reduced . To solve this problem this thesis proposed and described a grouping dimension-reduction method which combines hierarchy clustering with principal component analysis ( PCA ) .

针对慢性胃炎 病例数据的特点，提出并详细描述了层次聚类和主成分分析法相结合的 分组降维方法。

Patients were symptom score compared to before receiving treatment P0.05 indicating grouping the two groups were comparable condition .

两组患者在接受治疗前的 症状评分相比较，P值0.05，说明进行 分组时，两组患者的病情具有可比性。