Dear users,
I have this problem:
I have around 100 sites into my location where I need to go for a
technical survey...
I have already classified them using v.net.iso on the basis of the time
that I need to arrive there from my starting position....
so, at the moment, I have around 20 sites where I can arrive into half
an hour, 20 sites into one hour, and so on....
However, I know that I can't survey more than 4 or 5 sites for day,
coming back home at the evening...
so I need to combine these sites into groups, where each group contain 4
or 5 sites that are geographically near each other...
This way I could decide, each day, to survey the group1, than the next
day the group2, and so on.... avoiding a subjective choice of the sites
and allowing an optimisation of the survey planning...
I know that the problem can't give a unique solution.... but I hope that
someone can give me help or ideas (grass modules, shell
scripting,...) 
thanks to all
Ivan
--
Ivan Marchesini
Department of Civil and Environmental Engineering
University of Perugia
Via G. Duranti 93/a
06125
Perugia (Italy)
e-mail: marchesini@unipg.it
ivan.marchesini@gmail.com
tel: +39(0)755853760
fax: +39(0)755853756
jabber: geoivan73@jabber.org