Even if data visualization isn’t the primary goal of a project, adding an animated or interactive map can be an effective way to enrich a presentation, article, or lecture–and it doesn’t have to take up huge swaths of time. As part of the Tweeting Occupy Wall Street project, I tested web-based mapping tools that would allow us to plot some of the 10 million tweets related to Occupy Wall Street.
Dozens of geographic data visualization tools, many of them open-source, are available on the web, but for this particular project I investigated tools that are 1) powerful enough to handle large data sets; 2) relatively easy to learn and share; and 3) free. Here’s a rundown of the two tools that I found to be most effective in the Tweeting #OWS project: OpenHeatMap and Geocommons.
OpenHeatMap allows users to create static or animated heat maps (also called intensity or chloropleth maps) based on data uploaded through a Google Doc or Excel spreadsheet. Heatmaps plot values in a range of colors that indicate intensity, similarly to a meteorological radar map. One of the most user-friendly tools that I tested, all OpenHeatMap requires to generate a map is 1) location information, in the form of latitude and longitude or state/country abbreviations; 2) a column of values (used to plot intensity); and 3) if you want an animated heatmap, an optional column marked “time.”
Customization options in OpenHeatMap allow creators to control features like color and size of the data and map. After customizing, a user can simply use an autogenerated code to embed the map into an website. Alternatively, Open HeatMap offers an option to host the map on your own site and fully customize it using the Heatmap API. My attempt to do so was unsuccessful, however, and and a number of sources suggest simply using the embed code to store and share a map.
More than a site for creating maps, Geocommons is a robust data analysis, management, and visualization platform. Like its name suggests, Geocommons embraces the open-source model and strongly encourages users to make their maps and data public (20 megabytes of private data storage is also available with a free membership). This means that, along with uploading data, users can access hundreds of data sets including census data, zip code and county maps, and much more.
It’s possible to run analyses on data from within Geocommons, but I found it to be much faster to do the process in Excel or Google Docs first and upload the finished dataset that contained the values I wanted to plot. Geocommons makes it easy to aggregate data into non-map geographic visualizations, like this chart I make of the top states with Twitter activity related to Occupy Wall Street.