Kevin Quealy, graphics editor at the New York Times, has published another fascinating behind-the-scenes look at how the Times creates data visualizations for print and online. In his latest post, he looks at how a visualization of the Yankee's Mariano Rivera performance compared to other Major League Baseball pitchers was created. (Detail below, click for the full image.)
The infographic began its life as a hand-drawn sketch, that begat a line-chart created using R (based on data scraped from the Web). The R chart was was then cleaned up and annotated using Adobe Illustrator for publication. One interesting detail of the process: the source R graph is deliberately created using garish colours (purples, greens, etc.) to make the color-selection process easier in Illustrator.
Check out the ChartsNThings archive for other great studies of the process of data journalism. Many of the case studies involve the use of R code, such as these visualizations of visitors to the White House, Santorum's primary support, Santorum/Romney exit poll data, NFL players mentioned on ESPN, the defense budget and the richest 1%.