This is the result of an 8 day final project for DBC Chicago. Our team scraped over 140,000 headlines of several news agencies stretching back several years. We then took those headlines and fed them through the AlchemyAPI sentiment analysis engine to assign each one a score. They were then plotted in a couple different ways using D3.
This is far from perfect and even farther from scientific. It was done in 8 days by some passionate amateur developers. It was however a lot of fun and very interesting.
You can read about it and the team in more detail on the repo page here:
https://github.com/kelmerp/headline_sentiment_rating
and see some slightly more technical slides here:
https://speakerdeck.com/luizneves77/sentimental-headlines
This was written in RoR, Postgres (Memcached), and javascript + D3.
I'm also the creator of:
onionornot.com reddesigned.com http://luiz-n.github.io/route-search/
and am interviewing for web dev (and data visualization) positions in the chicago area if you would like to reach out to me. @hey_luiz