In case you have no experience in writing an R-package yourself  but would like to start developing one right away, this post might be helpful.I'm about to finish my first own (serious) R-package these days (more on the package itself later). Whil... [Read more...]

If you run an e-commerce site, blog or other web property there's a good chance you use Google Analytics to monitor traffic, look at visitor sources, and measure conversions. And while Google Analytics is quite powerful at looking at historic activity on your site, it lacks much in the way ... [Read more...]

A while ago I was asked to give a presentation at my job about using R to create statistical graphics. I had also just read some reviews of the Slidify package in R and I thought it would be extremely appropriate to create my presentation about visuali... [Read more...]

As a PhD student and researcher, I often hear friends and colleagues say that they want to learn R, but that the learning curve is so steep that they can't seem to get started.  It's true that learning any tool as powerful as R can be confusing at... [Read more...]

Have you ever seen these scatterplots that report a significant correlation between X and Y, and look like it’s just the one point to the upper-right driving the correlation? Thanks to this interactive tool, you too can do this at home. [Read more...]

In structural equation modelling, we are typically proposing theoretical causes of observed phenomena. These are termed "latent" (the unobserved causes) and manifest (the observed variables we measure, otherwise known as data).Importantly, the theoretical causes of behavior need not have a structure remotely resembling the correlations observed in the data. ... [Read more...]

Thanks to Gábor Csárdi, author of the R interface to ARPACK, for this example of using (the R/Igraph interface to) arpack for finding the largest eigenvalue of a matrix. The key insight is that arpack solves the function passed to … Continue reading → [Read more...]

When performing search engine marketing, it is usually beneficial to construct a system for making sense of keywords and their performance. While one could construct Bayesian Belief Networks to model the process of consumers clicking on ads, I have found that using ’tags’ to categorize keywords is just as useful ... [Read more...]

I've been writing software to help others do data analysis for a number of years and at the same time trying to work up my nerve to try my own analysis. Why let other people have all the fun? So, when I saw that Jeffrey Leek, biostatistician at Johns Hopkins ... [Read more...]

I am pleased to announce that together with Justin Meyer (also from the Wisconsin Department of Public Instruction) I will be presenting a two hour version of the R Bootcamp. Sector67 is a collaborative maker/hacker space in Madison, and is a great ven... [Read more...]

At Davis R Users’ Group today, Ryan Peek gave a presentation on how he takes data from his field instruments and visualizes it in R. Here are his notes. The original *.Rmd file and data can be found here SHORT HOW-TO ON USING XTS AND GGPLOT FOR TIME SERIES DATA ... [Read more...]

ProblemSet operations are a common place thing to do in R, and the enabling functions in the base stats package are:intersect(x, y)union(x, y)setdiff(x, y)setequal(x, y)That said, you'll note that each ONLY takes two arguments - i.e. set X and set ... [Read more...]

Modelling memory In the text below I present two models I've made to quantify and visualise the diverging trajectories of memory and news events, and conclude that linear regression may be used to test which model best describes the story. First, though, I contextualise this with an illustration from the ... [Read more...]

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If you're writing any significant amount of R code, you might want to start think about bundling it up into packages. An R package combines functions, data, documentation and unit tests, and is a convenient and reliable system to manage and version collections of R content that could otherwise become ... [Read more...]

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I bet you have seen this error a few times. When I compare large xts objects with different number of observations it would hit me right towards the end of the analysis.I wrote a small function, which allows me to check the length of the sets in advanc... [Read more...]

Some little birds had already been whispering about it, but I didn't want to jinx it and told myself I would wait with an announcement until the booksellers have (at least) placeholder pages. And as I learned from Duncan Murdoch via email earlier toda... [Read more...]

Say I have a list of values, and I cut them by some break points, how do I know the number of values in each interval?We know cut() function in R works for the purpose.  For example,tx0 [Read more...]

"Learning RStudio for R Statistical Computing" will teach you how to quickly and efficiently create and manage statistical analysis projects, import data, develop R scripts, and generate reports and graphics. R developers will learn about package development, coding principles, and … Continue reading → [Read more...]