如何将茎叶图转换为 R 中的数据集？

Question

The stem and leaf plot that I need to convert is given below-

24|9
23|
22|1
21|7
20|2, 2, 5, 5, 6, 9, 9, 9
19|0, 0, 0, 0, 0, 1, 1, 2, 4, 4, 5, 8
18|0, 1, 1, 2, 2, 2, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 9, 9, 9
17|1, 1, 1, 2, 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 9
16|0, 0, 1, 1, 1, 1, 2, 4, 5, 5, 6, 6, 8, 8, 8, 8
15|0, 1, 1, 1, 1, 1, 1, 5, 5, 5, 5, 6, 6, 6, 7, 7, 8, 9
14|0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 7, 7, 8, 9, 9
13|0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 8, 9, 9, 9
12|1, 1, 1, 2, 2, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 9, 9, 9
11|0, 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 5, 5, 6, 9, 9
10|0, 2, 3, 3, 3, 4, 4, 5, 7, 7, 8
9|0, 0, 9
8|6

Answer 1

Here's maybe one way. If your data looks like this

stem <- "24|9
23|
22|1
21|7
20|2, 2, 5, 5, 6, 9, 9, 9
19|0, 0, 0, 0, 0, 1, 1, 2, 4, 4, 5, 8
18|0, 1, 1, 2, 2, 2, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 9, 9, 9
17|1, 1, 1, 2, 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 9
16|0, 0, 1, 1, 1, 1, 2, 4, 5, 5, 6, 6, 8, 8, 8, 8
15|0, 1, 1, 1, 1, 1, 1, 5, 5, 5, 5, 6, 6, 6, 7, 7, 8, 9
14|0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 7, 7, 8, 9, 9
13|0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 8, 9, 9, 9
12|1, 1, 1, 2, 2, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 9, 9, 9
11|0, 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 5, 5, 6, 9, 9
10|0, 2, 3, 3, 3, 4, 4, 5, 7, 7, 8
9|0, 0, 9
8|6"

Then we can split up the rows and for each row we split by the pipe. Then we split the right side by commas and join each of those values to the value to the left of the pipe.

rows <- strsplit(stem,"\n")[[1]]
values <- unlist(lapply(strsplit(rows,"\\|"), function(x) {
  end_digits <- strsplit(x[2], ", ")[[1]]
  if (!all(is.na(end_digits))) {
    paste0(x[1], end_digits)
  } else {
    NULL
  }
}
))

This will return character values, but you could convert to numeric with

as.numeric(values)

Answer 2

Here is a different approach. Using @MrFlick's stem and rows objects:

rows <- strsplit(stem,"\n")[[1]]
rows.lst <- strsplit(rows,"\\|")
tens <- as.numeric(sapply(rows.lst, "[", 1)) * 10
ones <- sapply(strsplit(sapply(rows.lst, "[", 2), ","), as.numeric)
vals <- unlist(mapply("+", tens, ones))
vals <- vals[!is.na(vals)]