Adding a method to get indices of centroid molecules of clusters in BitBirch

[JianyuLi19]

Hi, I find this tool really good and fast. Could you please add a method to retrieve the index of all centroid molecules of all clusters in the BitBirch() class? This would be really helpful.

[klopezperez]

Hello
The centroids area not real molecules, then we do not have an index for them. The centroids are basically a virtual molecule created from the average bits in the cluster.

[ramirandaq]

Basically, the method would be to find, within each cluster, the molecule closest to the centroid, or use our iSIM package (https://github.com/mqcomplab/iSIM) to calculate the iSIM of each cluster.

[enordquist]

I am seconding this request to add a method to spit out "medoids". I am calculating the closest molecule to the centroid right now.