Overview

Teaching: 10 min
Exercises: 10 min

Questions

• What kind of scientific question does a line histogram address?

• How do I generate a line histogram with ggplot2?

Objectives

• To generate a line histogram using ggplot2

Walk through decision making steps from question to chart.

• “How was the population of Africa distributed across the continent by country in 2007?”
• Single variable distribution with many points
• Line Histogram

Implement line histogram.

• geom_histogram()
• geom_density()

Line Histogram Fill-in Challenge

Fill in the missing pieces of the following code to generate a line histogram.

ggplot(Africa, aes(________, ..count..)) +
  geom_density() ________
  labs(x = "Log10(________)", y = "Count")

Output Solution

Code Solution

ggplot(Africa, aes(log10(pop_2007), ..count..)) +
 geom_density() +
 labs(x = "Log10( 2007 Population )", y = "Count")

Key Points

• Line histograms represent a single variable distributions with many points.

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