# Stem-and-Leaf Plot

A stem-and-leaf plot of a quantitative variable is a textual graph that classifies data items according to their most significant numeric digits. In addition, we often merge each alternating row with its next row in order to simplify the graph for readability.

#### Example

In the data set faithful, a stem-and-leaf plot of the eruptions variable identifies durations with the same two most significant digits, and queue them up in rows.

#### Problem

Find the stem-and-leaf plot of the eruption durations in faithful.

#### Solution

We apply the stem function to compute the stem-and-leaf plot of eruptions.

The stem-and-leaf plot of the eruption durations is

> duration = faithful\$eruptions
> stem(duration)

The decimal point is 1 digit(s) to the left of the |

16 | 070355555588
18 | 000022233333335577777777888822335777888
20 | 00002223378800035778
22 | 0002335578023578
24 | 00228
26 | 23
28 | 080
30 | 7
32 | 2337
34 | 250077
36 | 0000823577
38 | 2333335582225577
40 | 0000003357788888002233555577778
42 | 03335555778800233333555577778
44 | 02222335557780000000023333357778888
46 | 0000233357700000023578
48 | 00000022335800333
50 | 0370

#### Exercise

Find the stem-and-leaf plot of the eruption waiting periods in faithful.