How can I cluster data?

Hi,

I have a set set of 3D data (i.e. X,Y,Z coordinates for each point). I would like to cluster these points into groups such that the distance from the centroid of the cluster to the point furthest from the center is not more than 10 nanometres. (i.e. radius of the cluster is not more than 10 nm). K-means doesn't seem particularity useful for this purpose as you have to specify the number of clusters.

Can anyone suggest a way to group points such that they are not separated by more than a specified distance?

[Ilya]

You need to specify additional constraints on the desired clustering solution. Based on what you said so far, turn every point into a separate cluster and you are done.