A couple weeks ago, I received an email from a fellow Pitch F/Xer and R-User, Josh Weinstock, asking if I was interested in a guest post here at Prince of Slides. I didn't think I was important enough to have talented guests posting at my blog; howeve...
The New York Times has created a beautiful visualization of the Census Bureau's 2005-2009 American Community Survey data. The distribution of racial and ethnic groups in New York City is particularly fascinating:Chinatown appears in red toward the sou...
I remember a few weeks ago, there was a challenge in the R-help list to make the prime symbol in R graphics. In LaTeX, we simply write $X'$ or $X^\prime$. R has a rough support for math expressions (see demo(plotmath)) and they are certainly unsatisfactory for LaTeX users. In fact we can write native LaTeX
I've always wanted to write a(n overly) simple model of evolution. The assumptions are minimalistic: only one species, for which each individual's genotype is represented as a one-dimensional real number, e.g. 7.4. Now, the fun stuff: I define a fu...
I thought of this after reading this post and perhaps also this one, one the Cheap Talk blog. Here's the puzzle: in general, being tall does not make you slow; but among professional tennis players, the tall athletes do tend to be relativel...
The first week of April I attended an excellent workshop on biplots held by Michael Greenacre and Oleg Nenadić at the Gesis Institute in Cologne, Germany. Throughout his presentations, Michael used animations to visualize the concepts he was explaining. He also included animations in some of his papers. This inspired me to do this post 
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 promise this is my last post on the now week and a half old π pay! Building on the last post, I figured I could show how convergence actually works in the estimation algorithm. If you’ll recall, we plotted … Continue reading →
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
