I don't fully understand why single link techinque in hierachial clustering is not good at handling (discovering) clusters of round or elliptical shapes. Simple examples will help me a lot. Thanks.
Asked
Active
Viewed 652 times
1
-
Each different hierarchical linkage method has its own inclinations wrt the shape of a cluster ("cluster metaphor", see pt 3 [here](http://stats.stackexchange.com/a/63549/3277)). Single linkage method is prone to "chain" and form clusters of irregular, often thread-like curved shapes. The reason for that is obvious. With this method, at any step, two clusters are merged if their closest edges are close enough. No proximity between _other_ parts of the two clusters is taken into consideration. – ttnphns May 31 '16 at 12:31
-
1(cont.) Therefore clusters that are far apart by their opposite poles easily get merged as being "close". That's why single link method is also called _nearest neighbour_ method. – ttnphns May 31 '16 at 12:31