[R] How to iterate through two objects of class "list" fast?

Peter Dalgaard p.dalgaard at biostat.ku.dk
Wed Jun 2 16:13:19 CEST 2004

"Wolski" <wolski at molgen.mpg.de> writes:

> list3[[x]] <- myfunc(list1[[x]],list2[[x]])
> Until now I am runnign this in a for(x in 1:length(list1)) loop. But "for" loops are slow especially if list3 is HUGE.
> What can I do?

Use mapply(). I wouldn't expect the for loop to be all that slow
unless you have forgotten to allocate memory for the result list up
front, though.

   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907

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