I played around with reverse dependencies of Rcpp. At the moment, 44 packages depend on Rcpp and the number goes up to 53 when counting recusive reverse dependencies. I've used graphviz for the representation of the directed graph Here is the c...

SabreR just released an update. It is another software package that can estimate multivariate multilevel model (other options are aML, MCMCglmm, etc.). They seem to also have a book dedicated to the software, which be worth checking out.It will be grea...

I just got the “news” that Dennis Ritchie died, although this happened on October 12… The announcement was surprisingly missing from my information channels and certainly got little media coverage, compared with Steve Jobs‘ demise. (I did miss the obituaries in the New York Times and in the Guardian. The Economist has the most appropriate

There have been several requests to an R User Group in Ireland, so thanks to Kevin O'Brien for stepping up to co-ordinate the Dublin-R group. Kevin invites all R users in the area to the first meeting on November 17: The Dublin R users group will be holding a series of monthly meetings. On the agenda is the development...

Everyday, a poor soul tries to understand copulas by reading the corresponding Wikipedia page, and gives up in despair. The incomprehensible mess that one finds there gives the impression that copulas are about as accessible as tensor theory, which is a shame, because they are actually a very nice tool. The only prerequisite is knowing

A recent question on one of the LinkedIn groups about the advantages of using R over commercial tools like SAS or IBM SPSS Modeller drew lots of comments for R. We like R a lot and we use it extensively, but I also wanted to balance the discussion. R is great, but looking at commercial organizations near...

A common approach to reducing risk associated with financial portfolios is diversification. A portfolio made of components that are all highly correlated with each other -- a portfolio composed solely of financial stocks, for example -- is risky, because if there's a wide-spread crisis that affects the banking sector, all components of the portfolio will tank at once, together....

In my previous post, I employed a rather crude and non-parametric approach to see if I could predict the direction of stock returns using the function runs.test(). Lets go a step further and try modelling this with a parametric econometric approach. The company that I choose for the study is INFOSYS (NSE code INFY). Lets start...

The “Minimum Correlation Algorithm” is a term I stumbled at the CSS Analytics blog. This is an Interesting Risk Measure that in my interpretation means: minimizing Average Portfolio Correlation with each Asset Class for a given level of return. One might try to use Correlation instead of Covariance matrix in mean-variance optimization, but this approach,

With R 2.14 slated to be released next week we wanted to encourage everyone planning to upgrade to also update to the latest release of RStudio (v0.94.110). For R 2.14 users this release includes tweaks related to compatibility with the R 2.14 graphics engine as well as compatibility with the new parallel package. There are

And now for something a bit more esoteric…. I recently wrote a function to deal with a strange problem. Writing the function ended up being a fun challenge related to computing on the R language itself. Here’s the problem: Write a function that tak...

The book is by Manfred Gilli, Dietmar Maringer and Enrico Schumann. I haven’t actually seen the book, so my judgement of it is mainly by the cover (and knowing the first two authors). The parts of the book closest to my heart are optimization, particularly portfolio optimization, and particularly particularly portfolio optimization via heuristic algorithms. … Continue reading...

Bubbles. I’m no expert in behavioral economics, but bubbles seem to be well understood (after they occur) although they seem hard to detect (at least in the eyes of outsiders and late bubble participants). This post won’t tell you how to avoid bubbles, but might give you some insight. I came across Minsky’s explanation of

For anyone who wants to estimate linear or nonlinear mixed-effects models (aka random-effects models, hierarchical models or multilevel models) using the R language, the Quantum Forest blog has several recent posts that will be of interest. Written by Luis Apiolaza from the School of Forestry at the University of Canterbury in New Zealand, the blog includes a number of...

Starting to write a blog I need a way how to publish my R codes. One possibility would be to just add some formatting with Pretty R. Nice, but I miss a repository with all codes ever submitted and possibility to make corrections.The final solution was ...