Is there any option to be as fast as the slowest stream for streams with different frequencies?

eg.

 

for streams

 

---x---y---z---t---u--->

-a-b-c-d-e-f-g-h-i-j-->

---o---o---o--o---o-->

f(a,x)

f(c,y)

f(e,z)

f(g,t)

f(i,u)

 

which is to invoke combination when both streams has a 'new' output. This may incur new problems such that observers may want to infer intermediate values for grouping like interpolations.