[R] finding clusters in a network

[JOHN VOIKLIS]

Hello,

I have data with 1500+ observations. Each observation has two
attributes _id_, a self identifier, and _parentid_, identifying a
single association with a previous observation. The value of
_parentid_ can either be the _id_ value of that single associated
observation or NA. Different observations can be associated with the
same previous observation and share the same value for _parentid_. In
this way, these 1500+ observations form a directed graph made up of
several disconnected clusters (of various sizes) and several isolates.
I need to identify these disconnected clusters of two or more
observations. I have been trying to figure out how to use the network,
sna, and kinship packages, but, without little time before finals to
read the relevant literature, I am desperate for some helpful advice.

Thank you in advance--

John