![Le Monde puzzle [52]](http://feeds.wordpress.com/1.0/comments/xianblog.wordpress.com/8586/)
The last puzzle of the year in Le Monde reads as follows (as far as I understand its wording!): Iter(n,x,y) is the function Iter=function(n,x,y){ if (n==1){ output=trunc(y/10)+x*(y%%10) }else{ output=Iter(n-1,x,Iter(1,x,y))} return output } Find the seven-digit number z such that Iter(6,1,z)=12, Iter(6,2,z)=19, Iter(6,3,z)=29, and Iter(6,-1,z)=Iter(6,-2,z)=Iter(6,-3,z)=0. Obviously, the brute-force solution of listing all 90 million seven digit 
I guess you could call this On Bayes Percentage. *cough*Fresh off learning Bayesian techniques in one of my classes last quarter, I thought it would be fun to try to apply the method. I was able to find some examples of Hierarchical Bayes being used to...
This post presents an RClimate script to develop a temperature sounding profile and calculate the ambient lapse rate using University of Wyoming atmospheric sounding data. Understanding atmospheric structure and lapse rate is essential to a full unders...
Jesse Bridgewater works on "social search awesomeness" for the Bing search engine, and is setting up his dev environment with the necessary tools including python, vim, and R. Jesse has shared a handy script he uses to install all the specialty packages he uses for his data analysis. This is a handy script to modify for your own purposes,...
The blog year started in August and consists of 30-something posts. Here is a summary. Quant concepts backtesting: Backtesting — almost wordless cointegration: American TV does cointegration efficient frontier: Anomalies meet volatility implied alpha: Implied alpha — almost wordless portfolio theory: Ancient portfolio theory random walk: The tightrope of the random walk returns: A tale … Continue reading...
The Facebook Data Team has published an analysis of the status updates of Facebook users, by categorizing words according to the 68 categories of the Linguistic Inquiry and Word Count Dictionary, and tabulating the frequencies of their use. It's fairly interesting to see this kind of analysis applied to Facebook, but unfortunately doesn't reveal much in the way of...
Following Ashley’s latest comments on Chapter 5 of Introducing Monte Carlo Methods with R, I realised Example 5.5 was totally off-the-mark! Not only the representation of the likelihood should have used prod instead of mean, not only the constant should call the val argument of integrate, not only integrate uses lower and upper rather than 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
