The On Broadway project collected more than 600,000 photographs taken near Broadway in New York City during a six-month period in 2014. If you're in New York, you can explore the images in an interactive installation at the New York Public Library though the end of this year. You can also explore them in your browser using this online app.
In addition to being part of the team that created the exhibit, artist Lev Manovich used R to analyze some of the data behind the project. For example, the timestamps of the photographs can be used to measure relative activity of the denizens of New York throughout the day (at least, those prone to post photos to social media). Here's a chart of activity measured by number of photos posted throughout the 24 hours of the day (clearly done as a polar coordinates chart with ggplot2):
From this data, it's clear there's not a lot happening between 3AM and 5AM. Of course, activity levels aren't constant across all of Manhattan: here's a comparison of "Tourist New York" (Broadway south of 110th St) on the left, and uptown Manhattan (above 110th street) on the right:
Wherever you look, though, it seems New York does sleep sometimes! You can explore more analysis of the data in Lev Manovich's blog post linked below.
Software Studies Initiative: "A City That Never Sleeps?" - new data and analysis from "On Broadway" project