Iterating over separate lists in R -

i have lots of variables in r, of type list

a100 = list() a200 = list() # ... p700 = list() 

each variable complicated data structure:

a200$time$data # returns 1000 x 1000 matrix 

now, want apply code each variable in turn. however, since r doesn't support pass-by-reference, i'm not sure do.

one idea had create big list of these lists, i.e.,

biglist = list() biglist[[1]] = a100 ... 

and iterate on biglist:

for (i in 1:length(biglist)){     biglist[[i]]$newstuff = "profit"     # more code here } 

and finally, after loop, go backwards existing code (that uses variable names) still works:

a100 = biglist[[1]] # ... 

the question is: there better way iterate on set of named lists? have feeling i'm doing things horribly wrong. there easier, like:

# fake, idealized code: foreach x in (a100, a200, ....){     x$newstuff = "profit" }  a100$newstuff # "profit" 

to parallel walk on lists can use mapply, take parallel lists , walk on them in lock-step. furthermore, in functional language should emit object want rather modify data structure within function call.

you should use sapply, apply, lapply, ... family of functions.

jim