Monday, April 16, 2012

Matrix Factorization in the News

In a tweet, Tim Davies wonders if our discovery of using a simple webcam and Robust PCA as a some sort of radiation detector and multichannel analyzer would not be a good thing as an app. The answer is that CCDs and CMOSs are a very inefficient way of detecting radiation. We use these videos as toy examples because they are taken in high radiation areas. Unless you know exactly the chip that witnesses the scene, the lack of calibration stops you from exactly figuring out what you see. But if you are looking for a cheap gamma spectrometer, you may want to invest $250 in this one.

In a different direction  Nelson Ray at MetaMarkets explains what Robust PCA is in: Algorithmic Trendspotting and the Meaning of "Interesting".

Finally, we learn that Netflix never used its $1 million algorithm due to engineering costs. The attendant Netflix blog entry: Netflix Recommendations: Beyond the 5 stars (Part 1) features the following more accurate statement:



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