For the last several weeks I’ve been experimenting with Tableau Public, a powerful, free software package for data analysis and visualization. I’m impressed by the software. It’s certainly the best free product I’ve worked with.
My big project on Tableau is an interactive graphic showing global mercury emissions by country and sector. I was able to get a nice dataset from the Arctic Monitoring and Assessment Program. These data were part of the 2013 UNEP Global Mercury Assessment. So they are very up-to-date, and with the adoption of the new Minamata Convention on Mercury, the topic is quite relevant. Good ingredients for an nice viz.
The graphic combines three elements: 1) a world map showing mercury emissions by country in a color gradient scale, 2) a tree map showing the mercury emissions of regions and their constituent countries as a part of total global emissions, and 3) a bar graph showing the makeup of emissions by industry sector for the world or selected countries. All the elements are linked so that selecting objects in one changes the other elements.