multiplicitiesoffreedom demonstrates Chaos Theory in Excel. If he filled in more initial values, you would see a thick bar—like a picture of white-noise. Butterflies flapping their wings in Vermont to change the wind in Hangzhou? A drop of water on ... [Read more...]

[Read more...]

Hollywood movies are obsessed with outrunning explosions and outrunning crashing alien spaceships. For explosions the movies give the optimal (but unusable) solution: run straight away. For crashing alien spaceships they give the same advice, but in this case it is wrong. We demonstrate the correct angle to flee. Running from ... [Read more...]

If I google for “probability distribution” I find the following extremely bad picture: It’s bad because it conflates ideas and oversimplifies how variable probability distributions can generally be. Most distributions are not unimodal. Most dist... [Read more...]

I do reports for clients with LyX and Sweave. It took me an extremely long time to get them working, but now that they’re working I can do more in an hour and thus charge more per hour. If you’re not familiar, here’s a rundown: LaTeX is ... [Read more...]

I was hoping to begin tinkering a bit with the multicore package in R beyond some extremely trivial examples.  Thanks to a combination of R’s dumb quirkiness (for example, being worthless on loops), my poor planning, and general bad programming, my Saturday afternoon tinkering project is ultimately worthless in ... [Read more...]

B*tchin’ six dimensional 6-cube. The rainbow colours and glass panes really help this visualisation.  Examples of 6-dimensional things If it’s hard to envision 6 dimensions, consider this: the possible tunings of a guitar constitute a 6-dimensio... [Read more...]

As you may know, today is Pi Day, when all good nerds take a moment to thank the geeks of antiquity for their painstaking work in estimating this marvelous mathematical constant. It is also a great opportunity to thank contemporary geeks for the wonders of modern computing, which allow us ... [Read more...]

Easiest way to start imagining four-dimensional things is by numbering the corners of a 4-cube. First realize that the eight corners of a cube can be numbered “in binary” 000—001–010–100—110–101–011—111. Just like the four corners of ... [Read more...]

Earlier this week I published a data visualization on the Facebook Engineering blog which, to my surprise, has received a lot of media covereage. I’ve received a lot comments about the image, many asking for more details on how I … Continue reading → [Read more...]

cumsum ( rnorm(50), lend="butt", lwd=12, type="h" ) Cumulative sum of 50 draws from a normal distribution. File this under mysteries of the Central Limit Theorem. [Read more...]

Central Limit Theorem A nice illustration of the Central Limit Theorem by convolution.in R: Heaviside 0,1,0) }HH [Read more...]

Here is how to improve your charts, graphs, maps, and plots: Erase non-data ink. Erase redundant data ink. Maximize the ratio of data to ink. Show data variation, not design variation. The surface area of graphical elements should be directly proportio... [Read more...]

Objective I’ll admit it: my résumé doesn’t stand out. I’ve had some great internships, but also a tendency to work for companies that aren’t (yet!) household names. And though I’m doing fine academically, it’s not well enough to stand out … Continue reading → [Read more...]

I first encountered the R programming language a few years ago when I needed to make some plots. Although I’ve used it occasionally since, I always considered it a sort of “Perl for statisticians” — a useful swiss-army knife with … Continue reading → [Read more...]

extrapolation and interpolation The most important lesson I learned from this book:  regression is reliable for interpolation, but not for extrapolation.  Even further, your observations really need to cover the whole gamut of causal variables, inter... [Read more...]

[Read more...]

For a long time I have been puzzled by the apparent lack of a comprehensive Open Source computer algebra software, i.e. what Octave is to MatLab and what R is to S. In other words, where is the Open Source … Continue reading → [Read more...]