Monthly Archives: December 2011

Code as Play

Cool project for teaching programming through web games: Play My Code

How to embed the game in the blog?

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Filed under education


I learned last week about a Python Package for doing MCMC estimation, called PyMCMC. It sounds sort of like something I’m always writing about, doesn’t it?

From my quick look, it appears that pyMCMC has some advanced sampling methods (like Slice sampling) that are not yet implemented for PyMC. On the other hand, it seems like PyMC has a more flexible modeling language, which permits formulation of complex models without writing out likelihood functions explicitly.

Has anyone used PyMCMC? How did it go for you?

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Filed under MCMC

Bitcoin and Anonymity

Bitcoin is intriguing, a digital currency where the entire transaction history of economy is held in common by all participants. I think that this will be a great observatory for research for someone. I read a recent paper that has some of the elements of this, An Analysis of Anonymity in the Bitcoin System by Fergal Reid and Martin Harrigan recently. As the name implies, it is mostly about the anonymity of the system. But it also includes a description of “the alleged theft of Bitcoins, which, at the time of the theft, had a market value of approximately half a million U.S. dollars”. That could be the plot of a good heist movie.

The paper led me to the bitcoin tools repository, which I’ll have to look into in more detail in the future.


Filed under Complex Networks

Complex Networks in the Kitchen

Two papers in the Arxiv caught my eye recently, (I have time to keep up on papers again!) both about networks and cooking.  Both came out around Thanksgiving, too, but maybe that is just a coincidence.

Chun-Yuen Teng, Yu-Ru Lin, Lada A. Adamic, Recipe recommendation using ingredient networks
Yong-Yeol Ahn, Sebastian E. Ahnert, James P. Bagrow, Albert-László Barabási, Flavor network and the principles of food pairing

They both have wonderfully complex network graphics, although the lack of information in these beautiful figures is acknowledged:

I’d love to combine this sort of analysis with the work on nutritional risk factors that has been going on around here recently. Did either of these papers come with a dataset I can explore?


Filed under Complex Networks

Teaching in Video Blips

Claire Mathieu has been blogging about intro math and CS videos from Khan Academy and from others:

I’ve heard about this Khan Academy, and it seems like more and more course material is appearing as tiny web videos.

Also I recently found out that there is a free, online version of the Stanford Intro AI Class taught by Peter Norvig and Sebastian Thrun, for which 56,000 students signed up. I think I accidentally did their homework.


Filed under education

False information

Ben Birnbaum stood for his general exam last week, on a topic that I’m very interested in:


Surveys are one of the principal means of gathering critical data from low-income regions. However, interviewer fabrication, or curbstoning, can threaten data quality. The existing literature lacks a set of general-purpose techniques to detect curbstoning; it does not capitalize on the potential of mobile data collection tools to help detect the phenomenon; and it provides few rigorous validations of the techniques that are developed. In this talk, I propose an anomaly detection framework to develop several general-purpose algorithms that identify curbstoning.

These algorithms can take advantage of the information in user traces from mobile data collection, a potential that I will evaluate rigorously. I also propose two studies to obtain high-quality labeled data sets with which I will validate my algorithms, thus partially filling the need for more rigorous evaluations.

Good job, Ben!  Also in attendance was Aram Harrow, who was reminded of this great story of the lying professor.  I wonder, could I could pull that off?

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Unscientific America

I read a short book about science and society last weekend, Unscientific America by Chris Mooney and Sheril Kirshenbaum. It’s a quick read, and the context is very much the 2008 elections, so you should browse it sooner than later. There are some good ideas, but the focus on web campaigns of 2008 are going to make them sound even more dated in a year.

The book argues strongly for the meaningful popularization of scientific ideas. I love the popularizers of science, and was very influenced by books like Surely You’re Joking, Mr. Feynman and Gödel, Escher, Bach when I was a youth. The modern history sections in Unscientific America trace these popularizations to Carl Sagan’s book/television series Cosmos. I should check that out.

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