R: stem and leaf plot issue - r

Question

I have the following vector:
x <- c(54.11, 58.09, 60.82, 86.59, 89.92, 91.61,
95.03, 95.03, 96.77, 98.52, 100.29, 102.07,
102.07, 107.51, 113.10, 130.70, 130.70, 138.93,
147.41, 149.57, 153.94, 158.37, 165.13, 201.06,
208.67, 235.06, 240.53, 251.65,254.47, 254.47, 333.29)
I want to get the following stem and leaf plot in R:
Stem Leaf
5 4 8
6 0
8 6 9
9 1 5 5 6 8
10 0 2 2 7
11 3
13 0 0 8
14 7 9
15 3 8
16 5
20 1 8
23 5
24 0
25 1 4 4
33 3
However, when I try the stem() function in R, I get the folliwing:
> stem(x)
The decimal point is 2 digit(s) to the right of the |
0 | 566999
1 | 000000011334
1 | 55567
2 | 0144
2 | 555
3 | 3
> stem(x, scale = 2)
The decimal point is 1 digit(s) to the right of the |
4 | 48
6 | 1
8 | 7025579
10 | 02283
12 | 119
14 | 7048
16 | 5
18 |
20 | 19
22 | 5
24 | 1244
26 |
28 |
30 |
32 | 3
Question: Am I missing an argument in the stem() function? If not, is there another solution?

Answer 1

I believe what you want is a little non-standard: a stem-and-leaf should have on its left equally-spaced numbers/digits, and you're asking for irregularly-spaced. I understand your frustration that 54 and 58 are grouped within the 40s, but the stem-and-leaf graph is really just a textual representation of a horizontal histogram, and the numbers on the side reflect the "bins" which will often begin/end outside of the known data. Think of scale(x, scale=2) left-scale numbers as 40-59, 60-79, etc.
You probably already tried this, but
stem(x, scale=3)
# The decimal point is 1 digit(s) to the right of the |
# 5 | 48
# 6 | 1
# 7 |
# 8 | 7
# 9 | 025579
# 10 | 0228
# 11 | 3
# 12 |
# 13 | 119
# 14 | 7
# 15 | 048
# 16 | 5
# 17 |
# 18 |
# 19 |
# 20 | 19
# 21 |
# 22 |
# 23 | 5
# 24 | 1
# 25 | 244
# 26 |
# 27 |
# 28 |
# 29 |
# 30 |
# 31 |
# 32 |
# 33 | 3
This is a good start, and is "proper" in that the bins are equally sized.
If you must remove the empty rows (which to me are still statistically significant, relevant, informative, etc), then because stem's default is to print to the console, you'll need to capture the console output (might have problems in rmarkdown docs), filter out the empty rows, and re-cat them to the console.
cat(Filter(function(s) grepl("decimal|\\|.*[0-9]", s),
capture.output(stem(x, scale=3))),
sep="\n")
# The decimal point is 1 digit(s) to the right of the |
# 5 | 48
# 6 | 1
# 8 | 7
# 9 | 025579
# 10 | 0228
# 11 | 3
# 13 | 119
# 14 | 7
# 15 | 048
# 16 | 5
# 20 | 19
# 23 | 5
# 24 | 1
# 25 | 244
# 33 | 3
(My grepl regex could likely be improved to handle something akin to "if there is a pipe, then it must be followed by one or more digits", but I think this suffices for now.)
There are some inequalities, in that you want 6 | 0, but your 60.82 is rounding to 61 (ergo the "1"). If you really want the 60.82 to be a 6 | 0, then truncate it with stem(trunc(x), scale=3). It's not exact, but I'm guessing that's because your sample output is hand-jammed.