Archives by date

You are browsing the site archives by date.

The FourierDescriptors Package

The FourierDescriptors Package

Introduction I’ve just uploaded a new package to CRAN based on a stimulus generation algorithm that I use for my experiments on vision. The FourierDescriptors package provides methods for creating, manipulating and visualizing Fourier descriptors, which are a representational scheme used to describe closed planar contours. The canonical reference from the literature is Zahn and […]

The Goddess Logical Rigor

Initiates into the mysteries of the goddess Logical Rigor use a strange speech among themselves, and find it all but impossible to communicate their visions to the mass of ordinary, unilluminated mankind. This accounts in part for the fact that, of the three disciplines most devoted to that goddess, analytical philosophy and neo-classical economics have […]

MCMC Diagnostics in R with the coda Package

MCMC Diagnostics in R with the coda Package

This is a follow up to my recent post introducing the use of JAGS in R through the rjags package. In the comments on that post, Bernd Weiss encouraged me to write a short addendum that describes diagnostic functions that you should use to assess the output from an MCMC sampler. I’ve only been using […]

Blegging for Data

I’m in the middle of a new project that involves analyzing the packages that are currently on CRAN. As part of my work, I could really benefit from information about which packages are installed on people’s computers. If you’re willing to part with a bit of your time and privacy, I’d very much appreciate you […]

Providence at Work

In August 2008, I commented on the remarkable incompetence of Blockbuster’s CEO. Now, in August 2010, it seems that we’re about to watch Blockbuster announce bankruptcy. It’s extraordinary how just the world can be at times.

ProjectTemplate

Introduction As many people already know, I’ve recently uploaded a new R package called ProjectTemplate to GitHub and CRAN. The ProjectTemplate package provides a function, create.project(), that automatically builds a directory for a new R project with a clean sub-directory structure and automatic data and library loading tools. My hope is that standardized data loading, […]

Using JAGS in R with the rjags Package

Get Everything Set Up I’m going to assume that you have access to a machine that will run JAGS. If you don’t, then you should be able to use WinBUGS, which is very easy to get set up. Unfortunately, the details of what follows may not help you as much if you’re using WinBUGS. To […]

Twifficiency Scores

Twifficiency Scores

Neil Kodner wrote a great post this morning about yesterday’s Twifficiency scores outbreak. He grabbed all the auto-tweeted scores he could find and plotted their distribution. I was struck by the asymmetry of the resulting distribution, which you can see below: Thankfully, Neil handed me the raw data for his plot, so I was able […]

Unit Testing in R: The Bare Minimum

Introduction This week I decided to start unit testing my R code, so I taught myself the bare minimum about the RUnit and testthat packages to be able to use them. Here’s what I found necessary to get started writing tests with both packages. RUnit Basic Example I’m going to assume that you’ve got a […]

Announcing Junebug

Today, my friend Jim Keller and I are officially opening our new dating site, Junebug, to the public. For the moment, we’re focusing on building a user base in the areas around Philadelphia and New York City, but the site is open to everyone in the US. If you’d like to check it out, please […]