How to use makeCloud and facetCylinder to generate random loose pack

Hi, guys

 I'm trying to make random loose pack in a cylinder container via makeCloud. I searched the manual and only found examples of making random loose pack in a facetBox, and it seems that makeCloud cannot use predicate either.

My question is:
1. Is it possible to get random loose pack via makeCloud and facetCylinder?
2. If not, how can I get a random loose pack in a cylinder?

ps. I'm new to Yade and I'm not sure if this was too basic or was already answered, but I do searched the mail list and found nothing relevant.

cheers,
Jian Wang