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Every one of us is unique! …You are unique!  there are sooo many people different from you… but at the same time, there are also A LOT that are damned similar to you… exhibiting the... [Read more...]

Last month I was ranting about the state of some of the examples in base-R, particularly the paste function. Martin Maechler has now kindly taken my suggested examples and added them into R. Hopefully this will reduce the number of newbie questions about “how do I join these strings together”. ... [Read more...]

I’m delighted that Professor Dianne Cook will be joining Monash University in July 2015 as a Professor of Business Analytics. Di is an Australian who has worked in the US for the past 25 years, mostly at Iowa State University. She is moving back to Australia and joining the Department of ... [Read more...]

X and Y are for XSLT, yacc and Yorick. XSLT is the tree climbing Kangaroo of the programming language world. Eating your own dog food is good practice for implementors, but users should not be forced to endure it. Anyway, people only use XML, rather than JSON, to increase the ... [Read more...]

In last weeks blog post introducing the new V8 package I showed how you can use context$eval and context$source to execute commands and scripts of JavaScript in R. It turns out that typing context$eval() for each JavaScript command gets annoying very quickly, so the new V8 version 0.3 ... [Read more...]

A new release of RcppEigen is now on CRAN, and will get to Debian shortly. This is thanks to a fabulous pull request by Yixuan Qiu who single-handedly managed to upgrade to the new minor release of Eigen -- after having expanded the unit tests a few ... [Read more...]

In this post, I’ll attempt to address a question I’ve seen tossed around time and again regarding quantstrat. “How do … Continue reading → [Read more...]

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For our purposes here, data exploration is the application of data visualization and data manipulation techniques to understand the properties of our dataset. We’re going to be looking for interesting features: things that stand out, trends, and relationships between variables. The post Data analysis example with ggplot and dplyr (... [Read more...]

I’m not sure how I came across it, but I have had Jez Liberty’s Au.Tra.Sy blog in my reader since around 2009. Since then, he has tracked well-known trend following systems and reported monthly performance figures. These are things like moving average crossovers, Bollinger band breakouts and ... [Read more...]

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It can be difficult to understand the functional relations between predictors and an outcome when using black box prediction methods like random forests. One way to investigate these relations is with partial dependence plots. These plots are graphical visualizations of the marginal effect of a given variable (or multiple variables) ... [Read more...]

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What if I told you there was a new drug that has been proven to DOUBLE your changes of getting over a cough? Sounds great doesn’t it? Well, before we (ahem) cough up the dough for drug X, let’s take a closer look at the clinical trial data: ... [Read more...]

Every year since her inauguration in 1952, Queen Elizabeth II has delivered a Christmas Broadcast to her subjects. Dominic Nyhuis used R to analyze the transcripts of the speeches, and found some interesting trends in speech length and words used. Here, for example, are word clouds of the speeches from the ... [Read more...]

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Adding a context can change one's frame of reference:Are you courteous? Are you courteous at work? Decontextualized questions tend to activate a self-presentation strategy and retrieve memories of past positioning of oneself (impression manag... [Read more...]

A new release of BH, our package providing (a large part of the) Boost C++ libraries as a set of template headers for use by R, is now on CRAN. There are two changes. First, we upgraded to Boost 1.55. While Boost 1.57 is now current, I am playing it ... [Read more...]

We have often been asked “why is there no Kindle edition of Practical Data Science with R on Amazon.com?” The short answer is: there is an edition you can read on your Kindle: but it is from the publisher Manning (not Amazon.com). The long answer is: when Amazon.... [Read more...]