# Back to back steam and leaf plot

I'm having a bit of trouble finishing up my back to back stem and leaf plot. I know what a back to back stem and leaf plot is and I also know how to make one but here is my question: When doing a back to back stem and leaf plot the stem is always in order like for example 1,2,3,4,5 or 12,13,14,15,16 and so on. What if let's say my stem starts on 0 and ends on 5 so it would be 0,1,2,3,4,5 but 3 and 4 on the stem have no leaf to go with it or data for it, do I still keep the 3 and 4 on the stem or do I skip them and do it like this 0,1,2,5?

My work

Do I do it like this:

    5|0|4,6,9
5,4|1|4,8
5,4,3|2|2,3,5
|3|
|4|
9,8|5|1


or should I do it like this:

    5|0|4,6,9
5,4|1|4,8
5,4,3|2|2,3,5
9,8|5|1


You skip, just like you have in the latter.

See http://www.basic-mathematics.com/stem-and-leaf-plot.html for more when the total scores are less than 100, and here http://www.purplemath.com/modules/stemleaf2.htm for when they're greater than 100.

$$\begin{array}{c|c|c} 5&0&469\\ 54&1&48\\ 543&2&235\\ 98&5&1 \end{array}$$

• Thanks for clearing things up for me! – J.Z May 6 '17 at 18:50
• I am not convinced skipping gaps is wise: it means that a glance (without reading the numbers) doe not show the distribution – Henry May 6 '17 at 19:34
• @Henry, It seems to be a matter of convention. I do believe you are correct. It can be a good idea to include the gaps, if you'd like to get a better idea of the distribution. – Chickenmancer May 6 '17 at 20:28
• So do I include the gaps? (In this case 3 and 4) – J.Z May 8 '17 at 22:02

According the results based on two R libraries, aplpack and graphics, we can see that both keep the gaps visible. Moreover, according the book ...

Probability and Statistics for Engineering and the Sciences 8th Edition, Jay L. Devore

one of the aspects which Stem and Leaf diagrams describes, is the occurrence of gaps in the data.

Result generated by aplpack:

stem.leaf.backback(data1, data2, m = 1, trim.outliers = FALSE, depths = FALSE)

5| 0 |469
54| 1 |48
543| 2 |235
| 3 |
| 4 |
98| 5 |1
| 6 |
___________________
n:    8     9