Histograms

Let’s consider the temp variable in the weather data frame once again. This time, we’ll only look at how the values of temp are distributed.

• What are the smallest and largest values?

• What is the center or most typical value?

• How do the values spread out?

• What are frequent and infrequent values?

One way to visualize the distribution of this single variable temp is to plot it on a horizontal line, as shown below:

This gives us a general idea of how the values of temp distribute. Observe that temperatures vary from around 11°F (-11°C) up to 100°F (38°C). Furthermore, there appears to be more recorded temperatures between 40°F and 60°F than outside this range. However, because of the high degree of overplotting in the points, it’s hard to get a sense of exactly how many values are between, say, 50°F and 55°F.

What is commonly produced instead of the diagram above is known as a histogram. A histogram is a plot that visualizes the distribution of a numerical value as follows: ...