r - 从strsplit列表中提取向量，而无需使用循环

Question

考虑以下 vector :

[1] "1-1694429" "2-1546669" "3-928598"  "4-834486"  "5-802353"  "6-659439"  "7-552850" 
"8-516804"  "9-364061" 
[10] "10-354181" "11-335154" "12-257915" "13-251310" "14-232313" "15-217628" "16-216569"   

我正在尝试生成两个 vector ，每个 vector 都包含通过用定界符“-”分割 vector 的每个元素而获得的值。

我用了:

f <- function(s) strsplit(s, "-")
cc<-sapply(names.reads, f)

head(cc) $1-1694429 [1] "1" "1694429"

$`2-1546669`

[1] "2"       "1546669"

我知道我可以像这样访问它们:

> cc[[1]][1]
[1] "1"

> cc[[1]][2]
[1] "1694429"

我想有两个 vector ，每个 vector 包含存储在 cc[[i]][1]和 cc[[i]][2]中的值...我可以不使用循环来做到这一点吗？ (我有超过一百万个元素)

Answer 1

使用math.coffee的建议，以下代码避免循环或sapply

names.reads <- c("1-1694429", "2-1546669", "3-928598", "4-834486", "5-802353",
              "6-659439",  "7-552850",  "8-516804", "9-364061", "10-354181",
              "11-335154", "12-257915", "13-251310", "14-232313", "15-217628",
              "16-216569")

cc       <- strsplit(names.reads,'-')
part1    <- unlist(cc)[2*(1:length(names.reads))-1]
part2    <- unlist(cc)[2*(1:length(names.reads))  ]

产生

> part1
 [1] "1"  "2"  "3"  "4"  "5"  "6"  "7"  "8"  "9"  "10" "11" "12" "13" "14" "15"
[16] "16"
> part2
 [1] "1694429" "1546669" "928598"  "834486"  "802353"  "659439"  "552850" 
 [8] "516804"  "364061"  "354181"  "335154"  "257915"  "251310"  "232313" 
[15] "217628"  "216569"

尽管它确实要求每个原始值都应采用预期的格式。