Hierarchical Clustering

[Aystein]

Hierarchical Clustering on selections is useful for exploring local structure, https://github.com/mljs/hclust/blob/master/src/agnes.js has an implementation for javascript. By altering the way a normal dendogram is drawn, this could be a neat technique

[keckelt]

I also suggest the following two additions to the current clustering/grouping behaviour:

If a new group is created, automatically connect it with existing related groups. That means:

• if the new group is part of another group (i.e., new group is a subset), or
• if the another group is part of the new group (i.e., new group is a superset)