折叠连续整数到范围的字符串 [英] Collapse continuous integer runs to strings of ranges

问题描述

我在列表中有一些数据需要寻找连续的整数（我的大脑认为 rle ，但在这里不知道如何使用它）。

I have some data in a list that I need to look for continuous runs of integers (My brain thinkrle but don't know how to use it here).

更容易查看数据集并解释我要做什么。

It's easier to look at the data set and explain what I'm after.

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

所需输出：

$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

使用基本软件包如何在高点之间用冒号代替连续跨度非连续部分之间的st和最低和逗号？请注意，数据从整数向量列表到字符向量列表。

Use base packages how can I replace continuous span with a colon between highest and lowest and commas in between non the non continuous parts? Note that the data goes from a list of integer vectors to a list of character vectors.

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"))

推荐答案

我认为 diff 是解决方案。您可能需要一些额外的摆弄来处理单例，但是：

I think diff is the solution. You might need some additional fiddling to deal with the singletons, but:

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"

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