www.necsi.edu/research/social/newyork
'Tweets are most positive near public parks ...
... The report, "Sentiment in New York City:
A High Resolution Spatial and Temporal View," by Karla Bertrand, Maya Bialik, Kawandeep Virdee, Andreas Gros and Yaneer Bar-Yam, created an algorithm to automatically classify tweets as positive or negative, and use their geotags and time information to paint a map.'
'None of this is surprising: who wouldn't be happy amidst the greenery of a public park '

New York's happiness, according to Twitter. The lighter the blue, the happier—the brighter