k-Medoid
This scatter graph sample illustrates k-medoids algorithm.
"The k-medoids algorithm is a clustering algorithm related to the k-means algorithm and the medoidshift algorithm. Both the k-means and k-medoids algorithms are partitional (breaking the dataset up into groups) and both attempt to minimize the distance between points labeled to be in a cluster and a point designated as the center of that cluster." [K-medoids. Wikipedia]
The scatterplot example "k-Medoid" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Scatter Diagrams solution from the Graphs and Charts area of ConceptDraw Solution Park.