Today we kick off Topic 2.b) Data Visualization by asking ourselves

What is a statistical graphic?

But a brief lesson from military history first:

In 1812, Napoleon led a French invasion of Russia, marching on Moscow.

It was one of the biggest military disasters ever, in particular b/c of the Russian winter.

Famous graphical illustration of Napolean's march to/from Moscow

This was considered a revolution in statistical graphics because between

• the map on top
• the line graph on the bottom

there are 6 dimensions of information (i.e. variables) being displayed on a 2D page.

A statistical graphic is a mapping of data variables to aes()thetic attributes of geom_etric objects.

Wilkinson (2005) laid out the proposed "Grammar of Graphics"

Wickham implemented the grammar in R in ggplot2 package

Another seminal book is Tufte's "The Visual Display of Quantitative Information"

Name this graph type!

From ggplot2movies package, the movies data set:

From nycflights13 package, the flights data set:

From fueleconomy package, the vehicles data set:

From babynames package, the babynames data set:

From okcupiddata package, the profiles data set:

Say hello to the 5NG: the five named graphs

1. Scatterplot AKA bivariate plot
2. Line-graph
3. Boxplot
4. Barplot AKA Barchart AKA bargraph
5. Histogram