Hierarchical clustering in astronomy

Hierarchical clustering is a common algorithm in data analysis. It unique among many algorithms that it draws dendrograms based on the distance of under certain metric, and group them. widely used all areas astronomical research, covering various scales from asteroids molecular clouds, to galaxies galaxy cluster. This paper systematically reviews history current status development hierarchical methods branches astronomy. These applications can be grouped into two broad categories, one revealing intrinsic structure celestial systems other classifying large samples objects automatically. By reviewing these applications, we clarify conditions limitations algorithm, make more reasonable reliable discoveries.