On the map, shades of red represent negative feelings, while shades of blue symbolize positive emotion.
During election week, the computer tracked tweets from supporters of President Barack Obama and former Gov. Mitt Romney. Based on the tweets, the computer produced a fairly accurate map — blue for Obama, red for Romney — of how Americans were feeling about the candidates.
The computer also tracked Hurricane Sandy tweets. The areas hit hardest by Sandy were the reddest.
The project is still continuing, and Twitter users can include the hashtag #tweetbeat in order to be tracked by the computer and shown on the live map.