A big thank-you to all the R users out there who voted for Revolution R Enterprise in DataWeek Awards. We're so pleased to be recognized by the voters and the DataWeek judging panel with the Top Innovator Award for Data Science Technology. We're looking forward to the awards ceremony next ... [Read more...]

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Alan brought up the suspicion to Ye’s world record in women 400 metres individual medley. And I quote: “Her last split caused controversy (deep suspicion of doping) as she swam it faster than the fastest male swimmer. I wonder how commonly this … Continue reading → [Read more...]

If you're writing C++ code and want to generate random numbers, you might not be aware that R provides an API to call the R RNG functionality directly. The Rcpp package's "syntactic sugar" feature makes this process easier, by automating the process of translating a subset of ordinary R code ... [Read more...]

I’ve been going through the medal statistics in London 2012 Olympics recently. I was planning to present some extra charts, such as medal-per-milli-population or medal-vs-GDP. However, it’s a little boring to present the same kind of charts. Thus, I’d like to look into some particular … Continue reading → [Read more...]

In this tutorial I am going to share my R&D and trading experience using the well-known from statistics Autoregressive Moving Average Model (ARMA). There is a lot written about these models, however, I strongly recommend Introductory Time Series with R, which I find is a perfect combination between light ... [Read more...]

People use the R language every day to create the elements of reports: tables, charts, analyses, and forecasts. But assembling all of that information into a print-ready document laid out with text can a hassle. You can cut-and-paste all of the elements into Word, but then what do you do ... [Read more...]

It’s almost midnight. Before I go sleeping, I’d like to post the chart about ”medals per event” on 2012 Olympics. As some visitors suggested, I searched for the competition information for each athlete. Finally, thankful to the mighty Guardian datablog, I find the … Continue reading → [Read more...]

Michael Bach, who is a professor and vision scientist at the University of Freiburg, maintains a fascinating site about visual illusions. One visual illusion really surprised me: the sigma motion. The sigma motion displays a flickering figure of bla... [Read more...]

Today I want to continue with Adaptive Asset Allocation theme and examine how the strategy results are sensitive to look-back parameters used for momentum and volatility computations. I will follow the sample steps that were outlined by David Varadi on the robustness of parameters of the Adaptive Asset Allocation algorithm ... [Read more...]

Last week's meeting of the Chicago area Hadoop User Group (a joint meeting the Chicago R User Group, and sponsored by Revolution Analytics) focused on crunching Big Data with R and Hadoop. Jeffrey Breen, president of Atmosphere Research Group, frequently deals with large data sets in his airline consulting work, ... [Read more...]

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I wrote before about heatmap tables as a better way of producing frequency or other tables, with a solution which works nicely in latex. It is possible to do them much more easily in ggplot2, like this library(Hmisc) library(ggplot2) library(reshape) data(HairEyeColor) P=t(HairEyeColor[,,2]) Pm=melt(... [Read more...]

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It’s the weekend. I just woke up from a nap. Got my mind freshed. I’d like to continue with my digging into the Olympics medal results. Today, I cited the number of participants from each country (see wikipedia). I want to see how … Continue reading → [Read more...]

Well I bought a new computer a month back (i7 8GB memory). Finally more than one core and a chance to try parallelization. I saw this blog post a while back and was intrigued and was further intriqued when I … Continue reading → [Read more...]

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Earlier this year data scientist Ryan Rosario gave a talk on parellel computing with R to the Los Angeles R User Group, and he recently made the slides from the talk available online. They're a great resource for anyone looking to make use of multi-processor systems a Hadoop based architechure ... [Read more...]

I’ve been spending a lot of time in the last month or so doing projects at work not statistics related, hence the lack of posts!  In the interim, I had to do some serious research on handling datasets bigger than … Continue reading → [Read more...]