我正在嘗試從數據框中對R中的列表進行子集劃分。我現在的嘗試是這樣的:R在子集化時加倍列表長度
list.level <- unique(buckets$group)
bucket.group <- vector("list",length(list.level))
for(i in list.level){
bucket.group[[i]] <- subset(buckets$group,buckets$group == i)
}
然而,除了填充列表似乎產生相同數量的行的副本列表,返回:
[[1]]
NULL
[[2]]
NULL
...
NULL
[[22]]
NULL
[[23]]
NULL
$A
[1] "A"
$C
[1] "C" "C" "C"
$D
[1] "D" "D" "D"
...
$AJ
[1] "AJ" "AJ" "AJ" "AJ" "AJ"
$AK
[1] "AK" "AK"
A應被充入1, C到2等等等等。我如何讓這些填充原始行而不是在列表底部創建額外的行?
你可以讓你的例子[reproducible?](http://stackoverflow.com/q/5963269/903061) – Gregor