On 09/20/2010 07:16 PM, Doran, Harold wrote:
> tmp1 <- tmp1[1:5,]
> tmp2 <- tmp2[1:5,]
> result <- rbind(tmp1, tmp2)
>
> Does anyone see a way to subset and subsequently bind without a loop?
>
> do.call(rbind,lapply(split(tmp,tmp$index),head,5))
index foo
1.11 1 -1.5124909
1.10 1 -1.3835811
1.20 1 -1.0906574
1.6 1 -0.8588022
1.8 1 -0.8384081
2.28 2 -2.9193984
2.36 2 -0.8782202
2.33 2 -0.7624129
2.38 2 -0.5995872
2.23 2 -0.5912392
(Sorry about the silly rownames.)
Or, (HACK ALERT!)
> tmp[ave(tmp$foo,tmp$index,FUN=seq_along)<=5,]
index foo
11 1 -1.5124909
10 1 -1.3835811
20 1 -1.0906574
6 1 -0.8588022
8 1 -0.8384081
28 2 -2.9193984
36 2 -0.8782202
33 2 -0.7624129
38 2 -0.5995872
23 2 -0.5912392
(The silly bit in this case being that you can only ave() a numeric
variable.)
Or maybe:
> tmp[unlist(tapply(seq_along(tmp$index), tmp$index, head,5)),]
--
Peter Dalgaard
Center for Statistics, Copenhagen Business School
Phone: (+45)38153501
Email: pd....@cbs.dk Priv: pda...@gmail.com
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