连续整数运行

Question

我在列表中有一些数据需要查找连续的整数运行(我的脑子想rle但不知道如何在这里使用它).

查看数据集并解释我所追求的内容会更容易.

这是数据视图:

$greg
 [1]  7  8  9 10 11 20 21 22 23 24 30 31 32 33 49

$researcher
[1] 42 43 44 45 46 47 48

$sally
 [1] 25 26 27 28 29 37 38 39 40 41

$sam
 [1]  1  2  3  4  5  6 16 17 18 19 34 35 36

$teacher
[1] 12 13 14 15

期望的输出:

$greg
 [1]  7:11, 20:24, 30:33, 49

$researcher
 [1] 42:48

$sally
 [1] 25:29, 37:41

$sam
 [1]  1:6, 16:19 34:36

$teacher
 [1] 12:15

使用基础包如何在最高和最低之间用冒号替换连续跨度,在非连续部分之间用逗号替换？请注意,数据从整数向量列表转到字符向量列表.

MWE数据:

z <- structure(list(greg = c(7L, 8L, 9L, 10L, 11L, 20L, 21L, 22L, 
    23L, 24L, 30L, 31L, 32L, 33L, 49L), researcher = 42:48, sally = c(25L, 
    26L, 27L, 28L, 29L, 37L, 38L, 39L, 40L, 41L), sam = c(1L, 2L, 
    3L, 4L, 5L, 6L, 16L, 17L, 18L, 19L, 34L, 35L, 36L), teacher = 12:15), .Names = c("greg", 
    "researcher", "sally", "sam", "teacher"))

Answer 1

我认为diff是解决方案.你可能需要一些额外的摆弄来处理单身人士,但是:

lapply(z, function(x) {
  diffs <- c(1, diff(x))
  start_indexes <- c(1, which(diffs > 1))
  end_indexes <- c(start_indexes - 1, length(x))
  coloned <- paste(x[start_indexes], x[end_indexes], sep=":")
  paste0(coloned, collapse=", ")
})

$greg
[1] "7:11, 20:24, 30:33, 49:49"

$researcher
[1] "42:48"

$sally
[1] "25:29, 37:41"

$sam
[1] "1:6, 16:19, 34:36"

$teacher
[1] "12:15"

Answer 2

使用IRanges:

require(IRanges)
lapply(z, function(x) {
    t <- as.data.frame(reduce(IRanges(x,x)))[,1:2]
    apply(t, 1, function(x) paste(unique(x), collapse=":"))
})

# $greg
# [1] "7:11"  "20:24" "30:33" "49"   
# 
# $researcher
# [1] "42:48"
# 
# $sally
# [1] "25:29" "37:41"
# 
# $sam
# [1] "1:6"   "16:19" "34:36"
# 
# $teacher
# [1] "12:15"

Answer 3

我对 Marius 有一个非常相似的解决方案，他的作品和我的一样，但机制略有不同，所以我想我不妨发布一下：

findIntRuns <- function(run){
  rundiff <- c(1, diff(run))
  difflist <- split(run, cumsum(rundiff!=1))
  unname(sapply(difflist, function(x){
    if(length(x) == 1) as.character(x) else paste0(x[1], ":", x[length(x)])
  }))
}

lapply(z, findIntRuns)

其中产生：

$greg
[1] "7:11"  "20:24" "30:33" "49"   

$researcher
[1] "42:48"

$sally
[1] "25:29" "37:41"

$sam
[1] "1:6"   "16:19" "34:36"

$teacher
[1] "12:15"

Answer 4

这是尝试使用diff并tapply返回字符向量

runs <- lapply(z, function(x) {
  z <- which(diff(x)!=1); 
  results <- x[sort(unique(c(1,length(x), z,z+1)))]
  lr <- length(results)
  collapse <- rep(seq_len(ceiling(lr/2)),each = 2, length.out = lr)
  as.vector(tapply(results, collapse, paste, collapse = ':'))
  })

runs
$greg
[1] "7:11"  "20:24" "30:33" "49"   

$researcher
[1] "42:48"

$sally
[1] "25:29" "37:41"

$sam
[1] "1:6"   "16:19" "34:36"

$teacher
[1] "12:15"

Answer 5

另一个简短的解决方案lapply和tapply：

lapply(z, function(x)
  unname(tapply(x, c(0, cumsum(diff(x) != 1)), FUN = function(y) 
    paste(unique(range(y)), collapse = ":")
  ))
)

结果：

$greg
[1] "7:11"  "20:24" "30:33" "49"   

$researcher
[1] "42:48"

$sally
[1] "25:29" "37:41"

$sam
[1] "1:6"   "16:19" "34:36"

$teacher
[1] "12:15"