Customizing Lines with ggplot2

Introduction to lines customization

It is possible to customize all the lines that are not a direct part of the plotted data, such as grid lines, axis lines, and others, using the element_line() function. Combining this function with the theme() function makes it possible to modify the appearance of lines like the x-axis and y-axis.

In general, the element_line() function allows us to change three sets of lines in a plot:

• The x-axis and y-axis lines
• Tick lines on the x-axis and y-axis
• Major and minor grid lines that run along both the x-axis and y-axis

Let’s first create a line chart with time series data using the gapminder dataset from the gapminder package, and then we’ll customize the chart.