[maxmsp] capturing snapshots during continuous (line) values

Hello ,

my problem:
I would like  to capture (isolate) singles values 
from a continous flow of values (gived by a line), and I wonder if it it exist a max object to achieve that.
(If not I guess that it can be feasible with some max patch)

any ideas ?

I hope my demand is clear

thank you 

Eryck  
--
www.eryckabecassis.com