Chen Xia and others put forward a clustering boundary point detection algorithm BORDER, whose boundary points are defined as follows:

Define boundary point: boundary point P refers to a data object that meets the following two conditions:

(1) It is located in the high density region IR;

(2) There is an area IR' near P, and the density (IR) >; > density (IR'), or

Density (IR) < & lt density (IR').

The boundary of clustering represents a potential pattern, which is of great significance to data mining. However, there are not many boundary algorithms involved at present, and the research on them is far from enough.

In DBSCAN algorithm, boundary points are mentioned: if a non-core point object falls within the Eps neighborhood of the core point, it is called a boundary point. Boundary points may fall into Eps neighborhood of one or more core points at the same time.

Boundary points in mathematics:

Interpretation of Advanced Mathematics of Tongji University, 6th Edition: If any neighborhood of point P contains both points belonging to E and points not belonging to E, then P is called the boundary point of E. ..