Manfred Schroeder's book Fractals, Chaos, Power Laws is a fruitful source of interesting topics and projects. He gives a thorough description of Diffusion-Limited Aggregation (DLA) as a technique for simulating physical processes which produce intricate branching structures. Examples, as illustrated below, include Lichtenberg Figures, dielectric breakdown, electrodeposition and Hele-Shaw flow. ... [Read more...]

Last week's Cologne R user group meeting was the best attended so far, and it was a remarkable event - I believe not a single line of R code was shown. Still, it was an R user group meeting with two excellent talks, and you will understand shortly why not ... [Read more...]

I love cars. The way they sound. The engineering. The craftsmanship. And let’s be honest: fast cars are just fun. Given my love of cars, I frequently watch Top Gear clips on YouTube. A couple of weeks ago, I stumbled across this:   Watching the video, I’m thinking, “253 miles ... [Read more...]

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I mentioned last week that I would be putting together a package, based in part on my posts on Snowdoop.  I’ve now done so, in a package partools., with the name alluding to the fact that they are intended for use with the cluster-based part of R’s parallel ... [Read more...]

I have some experience teaching R programming (see, for instance, my online course). One of the atypical choices I make is to start by teaching Hadley Wickham’s ggplot2 package, rather than the built-in R plotting (see these videos). Many times that I mention this choice to others involved in ... [Read more...]

Visualizing complex survey data is something of an art. If the data has been collected and aggregated to geographic units (say, counties or states), a choropleth is one option. But if the data aren't so neatly arranged, making visual sense often requires some form of smoothing to represent it on ... [Read more...]

My recent blog post, Why R is Hard to Learn, must have hit a nerve as it was read by over 6,000 people in its first two days online.  If you’re using R to augment your work in SAS, SPSS … Continue reading → [Read more...]

HTML tables are a standard way to display tabular information online. Getting HTML table data into R is fairly straightforward with the readHTMLTable() function of the XML package. But tables on the web are primarily designed for displaying and consuming data, not for analytical purposes. Peculiar design choices for HTML ... [Read more...]

An updated version of quantmod has just been released on CRAN.  This is my first submission as the new maintainer.  The major change was removing the dependency on the now-archived Defaults package.  End-users shouldn't notice ... [Read more...]

Admission: I didn’t really know how computers worked until around 2012. For the majority of my career, I’ve worked for large companies with centralized IT functions. Like many statisticians, I fell into a comfortable position of learning SAS in a Windows environment, had Ops people to fix any Unix ... [Read more...]

Data Community DC and District Data Labs are hosting a full-day Analyzing Social Media Data with R workshop on Saturday January 24th. For more info and to sign up, go to http://bit.ly/1FJjFIz. Register before January 9th for an early bird discount! [Read more...]

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Use our interactive tool to find out which airline has the most departures from your city The post Decide which frequent flyer program is best for your city appeared first on Decision Science News. [Read more...]

I spend a good amount of time on the programming Q+A site StackOverflow (and a smaller amount of time on its statistics sister site, Cross Validated). Recently this question on Meta Stack Overflow (the website’s discussion forum) caught my attention, raising the question of whether Stack Overflow had ... [Read more...]

Amongst today’s email was one from someone running a private competition to classify time series. Here are the essential details. The data are measurements from a medical diagnostic machine which takes 1 measurement every second, and after 32–1000 seconds, the time series must be classified into one of two classes. Some ... [Read more...]

A new release of the stringi package is available on CRAN (please wait a few days for Windows and OS X binary builds). # install.packages("stringi") or update.packages() library("stringi") Here’s a list of changes in version 0.4-1. In the current release,…Read more › [Read more...]

Agglomerative hierarchical clustering is a simple, intuitive and well-understood method for clustering data points. I used it with good results in a project to estimate the true geographical position of objects based on measured estimates. With this tutorial I would … Continue reading → [Read more...]

When I downloaded the KNMI meteorological data, the intention was to do something which takes more than just the computers memory. While it is clearly not big data, at the very least 100 years of daily data is not small either. So I took along a load o... [Read more...]

As a first step in visualizing/exploring the data from my last post, FOMC Dates - Scraping Data From Web Pages, I’ll plot the FOMC announcement dates along with the following price series: 2-Year and 10-Year US Treasury yields, S&P500 ETF (SPY) and USD Index ETF (UUP).I’... [Read more...]