I recently received an email about forecasting and rules of thumb. "Dans la profession se transmet une règle empirique qui voudrait que l'on prenne un historique du double de l'horizon de prévision : 20 ans de données pour une prévision

What are the alpha shapes?: “The concept of alpha shapes formalizes the intuitive notion of “shape” for spatial point set data, which occurs frequently in the computational sciences. An alpha shape is a concrete geometric object that is uniquely defined for a particular point set. Alpha shapes are generalizations of the convex hull. Given a

I am a regular reader of the FlowingData blog by Nathan Yau. It is an excellent reference for anyone interested in statistical visualization of data. One of his posts that caught my attention was a visualization of the growth of Walmart in the US. Given my research interests in retail, it was a fascinating insight

Catching up on roundups today. February roundup will follow soon, but in the meantime enjoy this trip down memory lane - DS. In case you missed them, here are some articles from January of particular interest to R users. Revolution Analytics is now offering annual sponsorship grants for local R user groups worldwide. Issue 2 of the R Journal...

Buried in the London Datastore are the population estimates for each of the London Boroughs between 2001 – 2030. They predict a declining population for most boroughs with the exception of a few to the east. I was surprised by this general decline and also the numbers involved- I expected larger changes from one year to ...

Today I unveil my very first statistical YouTube video! I will do anything to keep you statisfied, and if that means YouTube, then so be it. But first, some exposition: In Panama, 10 percent of the population owned 45 percent of the income in 2000, whereas the bottom 10 percent owned only 0.6 percent. How

We think of accidents as abnormal events, but there is “normal accident” theory. We don’t think of accidents happening in markets, but they do. That’s why it’s called a market crash. For normal accidents to come into play, two conditions need to hold: the system is complex the system is tightly coupled Certainly the financial … Continue reading...

Yesterday was the one-year anniversary of the Haiti earthquake, and to put the scale of the event in context San Francisco bureau chief for New Scientist magazine and data journalist Peter Aldhous created a time-lapse animation of all large earthquakes in the last year, beginning with the 7.0-magnitude Haiti event. Peter used USGS data, R and Flash to generate...