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Links for 2013-06-25

  • Liberty issues claim against British Intelligence Services over PRISM and Tempora privacy scandal

    James Welch, Legal Director for Liberty, said:   “Those demanding the Snoopers’ Charter seem to have been indulging in out-of-control snooping even without it – exploiting legal loopholes and help from Uncle Sam. “No-one suggests a completely unpoliced internet but those in power cannot swap targeted investigations for endless monitoring of the entire globe.”
    Go Liberty! Take note, ICCL, this is how a civil liberties group engages with internet issues.

    (tags: prism nsa gchq surveillance liberty civil-liberties internet snooping)

  • shades

    A command-line utility in Ruby to perform (a) OLAP cubing and (b) histogramming, given whitespace-delimited line data

    (tags: ruby olap number-crunching data histograms cli)

  • ‘If I was your cloud provider, I’d never let you down’

    This is the thing that’s put me off Joyent. They make claims like this one from October 2012:

    We’ve given our other partners 99.9999% uptime.
    This despite a 10-day outage of their BingoDisk and Strongspace storage services in January 2008, 1734 days previously ( If you assume that is the only outage they’ve had since then, that works out as 99.4% uptime. Quite a few less nines…

    (tags: joyent marketing uptime two-nines fail strongdisk)

  • js-hll

    Good UI for exploration of HyperLogLog set intersections and unions.

    One of the first things that we wanted to do with HyperLogLog when we first started playing with it was to support and expose it natively in the browser. The thought of allowing users to directly interact with these structures — perform arbitrary unions and intersections on effectively unbounded sets all on the client — was exhilarating to us. […] we are pleased to announce the open-source release of AK’s HyperLogLog implementation for JavaScript, js-hll. We are releasing this code under the Apache License, Version 2.0. We knew that we couldn’t just release a bunch of JavaScript code without allowing you to see it in action — that would be a crime. We passed a few ideas around and the one that kept bubbling to the top was a way to kill two birds with one stone. We wanted something that would showcase what you can do with HLL in the browser and give us a tool for explaining HLLs. It is typical for us to explain how HLL intersections work using a Venn diagram. You draw some overlapping circles with a border that represents the error and you talk about how if that border is close to or larger than the intersection then you can’t say much about the size of that intersection. This works just ok on a whiteboard but what you really want is to just build a visualization that allows you to select from some sets and see the overlap. Maybe even play with the precision a little bit to see how that changes the result. Well, we did just that!

    (tags: javascript ui hll hyperloglog algorithms sketching js sets intersection union apache open-source)

  • Sketch of the Day: K-Minimum Values

    Another sketching algorithm — this one supports set union and intersection operations more easily than HyperLogLog when there are more than 2 sets

    (tags: algorithms coding space-saving cardinality streams stream-processing estimation sets sketching)

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