[R] who to rbind of a list of data.frames
Peter Dalgaard BSA
p.dalgaard at biostat.ku.dk
Tue Aug 12 10:53:24 CEST 2003
lutz.thieme at amd.com writes:
> Hello everybody,
>
> could anybody give me a hint, who I can use rbind on a list of data.frames, please?
>
> I have a list with a large number of data.frames of the same structure, like:
> LIST <- list(X1=data.frame(a=1,b=2), X2=data.frame(a=3,b=4), X3=data.frame(a=5,b=6), ...., XN=data.frame(a=i,b=k))
>
> I would like to bind all data.frames very fast to a single data.frame, something like that:
> DF <- rbind(LIST$X1, LIST$X2, LIST$X3, ..., LIST$XN)
>
> But for performance (speed) reasons I won't use a loop. I also couldn't find a solution how
> I could use lapply. One constraint is, that the number of data.frames in the list is not determined
> and can vary from one to more than thousand.
> Any help is apreciated, thank you in advance.
Bill V.'s favourite trick:
do.call("rbind", LIST)
> Lutz Thieme
> Product Engineering
> AMD Saxony Limited Liability Company & Co. KG
Anyone tried getting R to run on Opterons in 64 bit mode BTW? Those
machines are quickly approaching Xeon prices around here..
--
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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