A friend of mine, who is quite smart by the way (she is a PhD. student in Physics at Cambridge), recently asked me for some help with Beamer. Well most of my knowledge and code came from Utkarsh when I had started about a year ago. Initially, I ha...
Let's talk about R in the insurance industry today. David Smith's blog entry reminded me about our poster at the R user conference in Warwick in August 2011:Using R in InsuranceWe presented examples on how R can be used in the insu...
Revolution Analytics' Joe Rickert has a new post on inside-R.org, demonstrating how you can use R and the RevoScaleR package to extract time series data from time-stamped logs (in this case, the "US Domestic Flights From 1990 to 2009" dataset on Infochimps): Analyzing time series data of all sorts is a fundamental business analytics task to which the R...
Note: This post is NOT financial advice! This is just a fun way to explore some of the capabilities R has for importing and manipulating data. In my last post, I demonstrated how to backtest a simple momentum-based stock trading strategy ...
Some pictures to explore the reality of the theory that stocks with higher beta should have higher expected returns. Figure 2 of “The effect of beta equal 1″ shows the return-beta relationship as downward sloping. That’s a sample of size 1. In this post we add six more datapoints. Data The exact same betas of … Continue reading...
update Henrik Bengtsson commented that which(x, arr.ind=TRUE) gives the same result, rendering the blog below academic (thanks for the comment!). So, for academic interest, I'll leave it. In my defense, I implemented this kind of functionality in C some time … Continue reading →
The well-known which function accepts a logical vector and returns the indices where its value equals TRUE. Actually, which also accepts matrices or multidimensional arrays. Internally, R uses a single index to run through such two- or higher-dimension...
Users of our Google Earth interface to USDA-NCSS soils information will now see links to soil-landscape block diagrams listed within map unit descriptions. Automated Linking to NCSS Block Diagrams read more
I have a paper which I wrote some years ago, which has not been finished, and which should be accompanied by an R package. So far nothing special, but at that time, I was only at the beginning of my affair with R, and so I made several mistakes (OK – I did also some 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
