As promised, I got back to this book, Implementing reproducible research (after the pigeons had their say). I looked at it this morning while monitoring my students taking their last-chance R exam (definitely last chance as my undergraduate R course is not reconoduced next year). The book is in fact ... [Read more...]

An easy way to run R code in parallel on a multicore system is with the mclapply() function. Unfortunately, mclapply() does not work on Windows machines because the mclapply() implementation relies on forking and Windows does not support forking. For me, this is somewhat of a headache because I am ... [Read more...]

As a follow-up to my post about major changes to FSA and that some of the “old” vignettes are now out-of-date, here is a brief summary of new material in the draft book chapters (linked to below) that replaced the … Continue reading → [Read more...]

I have a classification task and was reading up on various approaches. In the specific case where all inputs are categorical, one can use “Bayesian Naïve Bayes” using the Dirichlet distribution.  Poking through the freely available text by Barber, I found a rather detailed discussion in chapters 9 and 10, as ... [Read more...]

InsideBigData has published a new Guide to Machine Learning, in collaboration with Revolution Analytics. As the name suggests, the Guide provides an overview of machine learning techniques, with a focus on implementation with the R language and (for big-data applications) Revolution R Enterprise. You can download the Guide here (email ... [Read more...]

R's semantics is modeled after Scheme. Scheme is a functional language and R is functional too. I am writing about the functions in R and many R's strange usages are just syntax sugars of special function calls. What is rownames(x) [Read more...]

Hi all I’m James. This is my first blog for Coppelia. Thanks to Simon for encouraging me to do this. I’ve been doing a lot of hierarchical clustering in R and have started to find the the standard dendrogram plot fairly unreadable once you have over a couple ... [Read more...]

This is the bimonthly R Jobs post (for 2014-07-14), based on the R-bloggers’ sister website: R-users.com. If you are an employer who is looking to hire people from the [Read more...]

By popular demand, I updated the fantasy football draft optimizers with 2014 projections.  There are two draft optimizers (one for auction drafts and one for snake drafts).  The optimizers identify[...] The post Win Your Fantasy Football Draft with These Shiny Apps: 2014 Update appeared first on Fantasy Football Analytics. [Read more...]

Setting the right random effect part in mixed effect models can be tricky in many applied situation. I will not talk here about choosing wether a grouping variable (sites, individuals …) should be included as a fixed term or as a random term, please see Gelman and Hill (2006) and Zuur et ... [Read more...]

I thought it would be fun to fit a simple model in Stan to estimate the abilities of the teams in the World Cup, then I could post everything here on the blog, the whole story of the analysis from beginning to end, showing the results of spending a couple ... [Read more...]

Mathematics is the art of giving the same name to different things (Henri Poincare) Many surveys among experts point that demonstration of the Riemann Hypothesis is the most important pending mathematical issue in this world. This hypothesis is related to Riemann zeta function, which is supossed to be zero only ... [Read more...]

Often when working, we are under deadlines to produce results in a reasonable timeframe. Sometimes an analyst may not check his assumptions if he is under a tight deadline. A simple example to illustrate this would be a one sample … Continue reading → [Read more...]

While I was out at the (immensely impressive and equally enjoyable) useR! 2014 conference at UCLA, Conrad provided a bug-fix release 4.320 of Armadillo, the nifty templated C++ library for linear algebra. I quickly rolled that into RcppArmadillo rel... [Read more...]

Two short items in this blogpost. Since it was not obvious how to run odfWeave() in my particular setup, the call I am using. Then there were several people crosstabulating logical vectors, so I wanted to play along, 80 times faster than table().odfWeaveMy particular setup consists of R, 7-zip, libreoffice. ... [Read more...]

  R is different from C family languages. It has a C syntax, but a Lisp semantics. Programmers from C/C++/Java world would find many usages in R adhoc and need to memorize special cases. This is because they use R from a C's perspective. R is a very elegant ... [Read more...]

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I’m the first to acknowledge that most of my code could run faster. The truth of the matter is that, in essence, I write ‘quickies’: code that will run once or twice, so there is no incentive to spend days or hours in shaving seconds of a computation. Most ... [Read more...]

IEEE — the world's largest professional association for the language of technology — recently published its ranking of the popularity of programming languages. The R language comes in at number 9 in the list. The ranking is based on 12 weighted factors, including Google search rankings and trends, social media chatter, aggregator posts (Reddit ... [Read more...]

Monday, I will be giving the closing talk of the R in Insurance Conference, in London, on Bayesian Computations for Actuaries, as to be more specific, Getting into Bayesian Wizardry… (with the eyes of a muggle actuary). The animated version of the slides (since we will spend some time on ... [Read more...]