At last weekend’s Hack Ta Ville event here in Montreal, I joined up with some talented urban planners and web devs to realize Vélobstacles. The idea of the project is to crowd source information on cycling conditions around the city. As with any crowd sourcing project, we were ... [Read more...]

Michael Bach, who is a professor and vision scientist at the University of Freiburg, maintains a fascinating site about visual illusions. One visual illusion really surprised me: the sigma motion. The sigma motion displays a flickering figure of bla... [Read more...]

[Read more...]

[Read more...]

[Read more...]

Shown above is a queueing simulation. Each diamond represents a person. The vertical line up is the queue; at the bottom are 5 slots where the people are attended. The size of each diamond is proportional to the log of the time it will take them to be attended. Color is ... [Read more...]

[Read more...]

[Read more...]

In undergrad I had a computer science professor that piqued my interest in applied mathematics, beginning with Conway’s Game of Life. At first, the Game of Life (not the board game) appears to be quite simple — perhaps, too simple — but it has been widely explored and is useful for ... [Read more...]

he formatR package has been silent for quite a few months now. Recently I’ve been moving my old packages from R-Forge to GitHub, and I finally killed several things on my TODO list. In the past, I made an awkward decision to let formatR depend on the animation package, ... [Read more...]

As every useR knows, the useR! 2010 conference is being held at NIST in Gaithersburg these days. I have just finished my talk on the R package animation this afternoon. Here are my slides and R code for those who are interested: Have fun, even if you are a PhD! Related ... [Read more...]

Before I decided to learn R in a serious way, I thought about learning Flash/Actionscript instead. Most of my work involves evolutionary models that take place over time. I need visual representations of change. It’s certainly possible to represent change and tell an evolving story with a single ... [Read more...]

new paper on the α-convex hull appeared in the Journal of Statistical Software today (http://www.jstatsoft.org/v34/i05/paper). The α-convex hull is an interesting problem which caught my attention long time ago but I didn’t know a solution then. R has a function chull() which can ... [Read more...]

mber Watkins gave me a suggestion on the animation for the ratio estimation, and I think this is a good topic for my animation package. I’ve finished writing the initial version of the function sample.ratio() for this package, which will appear in the version 1.1-2 a couple of ... [Read more...]

I have to admit that the previous post on Christmas is actually not much fun. Today I received another pResent from Yixuan which is more interesting: Basically the code deals with letter polygons (i.e. glyphs) and plot them with proper projections from 3D to 2D space: ## original code by ... [Read more...]

Duncan Murdoch just posted a youtube video presenting an animation clip of a 3d rgl object. Duncan even went further and wrote an explanation on how he made the video: here are the steps I used: 1.  Design a shape to be displayed, and then play with the animation functions to ... [Read more...]

ince animation 1.0-9, we will be able to create a PDF document with an animation embedded in it; the function is saveLatex(), and its usage is similar to saveMovie() and saveSWF(): you pass an R expression for creating animations to this function, and this expression will be evaluated in the ... [Read more...]

oday Romain Francois posted an interesting topic in the R-help list, and you can read his blog post for more details: celebrating R commit #50000. 50000 is certainly not a small number; we do owe R core members a big “thank you” for their great efforts in this fantastic statistical language in ... [Read more...]

inlin Yan posted a cool (hot?) simulation of burning fire with R in the COS forum yesterday, which was indeed a warm welcome. I’m not sure whether our forum members will be scared by the “fire” under the title “Welcome to COS Forum”. The fire was mainly created by ... [Read more...]