Four short links: 5 November 2009

Heat Maps in R, EC2 Blackhat Tricks, Snickersome Unicode, and Decoding Statistics

  1. Heat Maps in RWe used financial data here because it’s easier to access than the airline data, but it’s actually a pretty interesting way of looking at a financial time series. Weekend and holiday effects are a bit more obvious, and it’s a bit like being able to see the daily, weekly, monthly and yearly closes all at once (by scanning your eye over the calendar in different directions). Includes source code. (via migurski on Delicious)
  2. BlackHat and EC2Theft of resources is the red-headed step-child of attack classes and doesn’t get much attention, but on cloud platforms where resources are shared amongst many users these attacks can have a very real impact. With this in mind, we wanted to show how EC2 was vulnerable to a number of resource theft attacks and the videos below demonstrate three separate attacks against EC2 that permit an attacker to boot up massive numbers of machines, steal computing time/bandwidth from other users and steal paid-for AMIs. (via straup on Delicious)
  3. Funny Characters in Unicode — I never get tired of the wacky stuff in Unicode. I love the thought of a Unicode committee somewhere arguing passionately about the number of buttons on the snowman …. (via Hacker News)
  4. Statistics to English TranslationThe terms sensitivity and specificity generally refer to diagnostic or screening procedures, such as an HIV or allergy tests. The sensitivity of a test is its true positive rate; the specificity is its true negative rate, although it can be more intuitive to think of specificity as the complement of the false positive rate. This matters. Bandying around numbers with misleading labels, or misinterpreting numbers that have a precise and defined meaning, does not further understanding. (Said 78.4% of statisticians, with a 20% confidence factor probability of false positives)

 

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