# My boxplot shows a box but no whiskers

## 2022-12-15

One of my favorite graphs is the box plot. It is a visualization of a five number summary. Those five numbers are minimum, 25th percentile, median (aka the 50th percentile), 75th percentile, and maximum. The box in a box plot extends from the 25th to the 75th percentile and a line inside the box represents the median.

It’s great for comparing two groups. Here’s a boxplot showing two groups. Notice that the first group tends to have larger values.

##            x  g
## 1  0.5373604 g1
## 2  0.6169055 g1
## 3  0.6716831 g1
## 4  0.7156946 g1
## 5  0.7538330 g1
## 6  0.7885528 g1
## 7  0.8214372 g1
## 8  0.8538300 g1
## 9  0.8873732 g1
## 10 0.9253821 g1
## 11 0.3943692 g2
## 12 0.4710208 g2
## 13 0.5267383 g2
## 14 0.5735105 g2
## 15 0.6157184 g2
## 16 0.6557301 g2
## 17 0.6952916 g2
## 18 0.7362077 g2
## 19 0.7812077 g2
## 20 0.8368375 g2


What happens if you try to compute the five number summary with a dataset that only has only two values?

##            x  g
## 1  0.5373604 g1
## 2  0.6169055 g1
## 3  0.6716831 g1
## 4  0.7156946 g1
## 5  0.7538330 g1
## 6  0.7885528 g1
## 7  0.8214372 g1
## 8  0.8538300 g1
## 9  0.8873732 g1
## 10 0.9253821 g1
## 11 0.5585801 g2
## 12 0.7086762 g2