Strata Week: Grabbing a slice

Digits of pi, extruding images with iPads, and mapping the past on top of the present

Reminder: This is the last week to submit proposals for O’Reilly Strata; the call ends on Sept. 28. We’re eager to hear your stories about the business and practice of data, analytics and visualization, so submit a proposal now.

A bigger slice of pi

A team led by Nicholas Sze of Yahoo! has calculated the 2,000,000,000,000,000th digit of pi, more than doubling the previous record. Extreme computational power helped — Sze employed a cluster of 1,000 Hadoop machines to do in 23 days what would have taken 500 years on a standard PC — but so did a non-traditional approach. Instead of working linearly from the decimal point, Sze used MapReduce to calculate isolated portions of the mathematical constant and express them in binary.

Aside from earning serious nerd-cred and bragging rights, the exercise proves handy in practical terms, too.

“This kind of calculation is useful in benchmarking and testing,” Sze told the BBC. “We have used it to compare the [processor] performance among our clusters.”

The iPad’s slice of light

Dentsu London and BERG have developed an impressive technique that uses iPads to extrude light paintings by dragging the device across a long exposure shot as it flashes consecutive single cross-sections of a 3D model.

Making Future Magic: iPad light painting from Dentsu London.

Stephen Von Worley at Data Pointed asks whether a similar but reverse technique might be used by doctors to explore digital body scans by moving an iPad through the space of a fixed block of data in order to explore it.

To my knowledge, no one is yet doing that, but it seems just the kind of technique that could be considered by the team at Linköping University in Sweden. That group is working with digital body scans to create cut-free autopsies.

A different slice of life

Historypin, a photo project of We Are What We Do in collaboration with Google, has recently released The Blitz Collection. The idea behind Historypin is to build a catalog of public-space photos that can be searched by place, subject matter, or time. Users can upload their own photos and “pin” them to a map, adding contextual information about time or topic that other users can then access. The best part, though, is being able to view historical photos “pinned” to modern-day Google Street View images of the same place.

The Blitz Collection is a special set of these images meant to commemorate the 70th anniversary of the bombing of London and other cities across Britain during WWII.

An image of St. Stephen’s Street in Norwich, dated April 28, 1942.

Historypin’s next group project will be to collect American Civil Rights photos in celebration of Dr. Martin Luther King Jr.’s “I Have a Dream” speech, so start searching your attics and family photo albums.

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