Many statistical algorithms are taught and implemented in terms of linear algebra. Statistical packages often borrow heavily from optimized linear algebra libraries such as LINPACK, LAPACK, or BLAS. When implementing these algorithms in systems such as Octave or MATLAB, it is up to you to translate the data from the ... [Read more...]

What makes this book different from other books about R is stated clearly by the author Norman Matloff in the introduction: "This book is not a compendium of the myriad types of statistical methods that are available in the wonderful R package. It r... [Read more...]

How do volatility estimates based on monthly versus daily returns differ? Previously The post “The mystery of volatility estimates from daily versus monthly returns” and its offspring “Another look at autocorrelation in the S&P 500″ discussed what appears to be an anomaly in the estimation of volatility from daily versus ... [Read more...]

I think one of the real reasons that I haven't liked R is the default interface blows (sucks, whatever).  I just discovered the Eclipse plugin StatET.  This things rules.  Contextual help, completion, object browser, data browser, etc. &... [Read more...]

Given that there are almost 13 million views of Steve Jobs’ commencement address, I am certain that I missed this video when it went viral. I am glad that I did not see it until now because I may not have appreciated his words of wisdom. And although... [Read more...]

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Let me preface this post by saying I am getting frustrated with R.  The syntax is not intuitive and the performance for matrix operations is slow.  Using Octave, a free Matlab clone, I can get over 6 Gflops on things that R is doing at less than 2.  After this post, I ... [Read more...]

So recently Bureau of Labor Statistics released the Oct. 2011 unemployment data. This is not a discussion of it’s validity nor it’s impact, but it is a post on how to visualize it. This post is also for my posterity, I’ve wanted to be able to do this ... [Read more...]

Things have been a bit quiet at Quantum Forest during the last ten days. Last Monday (Sunday for most readers) I flew to Australia to attend a couple of one-day workshops; one on spatial analysis (in Sydney) and another one … Continue reading → [Read more...]

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It is not as if I don't have enough books (and material on the web) to read. But this list compiled by the O'Reilly team should make any data analyst salivate.http://shop.oreilly.com/category/deals/data-science-kit.doThe Books and Video included in the... [Read more...]

A common task when analyzing multi-group designs is obtaining descriptive statistics for various cells and cell combinations. There are many functions that can help you accomplish this, including aggregate() and by() in the base installation, summaryBy() in the doBy package, and … Continue reading → [Read more...]

The revision period for the Applications of R in Business Contest is now at a close, and the competitors have finalized their entries for a chance at $20,000 in prizes from Revolution Analytics. We're now in the judging phase, where the finalists will be rated on applicability to business, innovation and ... [Read more...]

Happy last month of 2011. I will fly to Sydney to present a paper at the 24th Australasian Finance & Banking Conference on next Thursday, so we may not have a review next week. However, feel free to contact me @a_biao for sharing any useful post. This week's review is highly ... [Read more...]

Computer Assisted Reporting This technical note describes manipulation/analysis of Wisconsin voter registration data from June 2011. Wisconsin voter registration data can be purchased from the Wisconsin Government Accountability Board for $12,500, whic... [Read more...]

Alright, I better start with an apology for the title of this post. I know, it’s really bad. But let’s get on to the good stuff, or, perhaps more accurately, the really frightening stuff. The plot shown at the top of this post is a simulation of the ... [Read more...]

I want to illustrate Backtesting with Short positions using an interesting strategy introduced by Woodshedder in the Simple, Long-Term Indicator Near to Giving Short Signal post. This strategy was also analyzed in details by MarketSci in Woodshedder’s Long-Term Indicator post. The strategy uses the 5 day rate of change (ROC5) ... [Read more...]

For those looking for more background behind the updates in Revolution R Enterprise 5.0, there are now a couple of interviews online where I talk about the new release. At IT Business Edge ("Revolution Analytics' Goal: Make R Analysis Enterprise-Friendly"), I had a chat with Loraine Lawson about how Revolution R ... [Read more...]

Just a brief selection of items that caught my eye this week. Note that this is a Friday as opposed to Friday, lest you mistake this for a new, regular feature. 1. R/statistics ggbio A new Bioconductor package which builds on the excellent ggplot graphics library, for the visualization of ... [Read more...]