thanks for your suggestions, it works better now
for non-negative input you will get the same output from [%~ 1.], as from wrap~. However, for the whole domain, wrapping pong~, [pong~ 1], does the job (although it costs more)
Krzysztof
the difference is only if you put a negative sig number you get a negative modulo ([-1;0] instead of [1;0]). so if you need positives numbers when you put negatives one ( a la [wrap~]) you must to use a detection of negatives [<~ 0] then a gate~ (or other thing) then [abs~ ] with some [-~ 1] after [%~ 1].
Hope is comprehensible and excuse my english, if you want I can send you an example.
José