Bob O’Hara has written a nice article for The Guardian explaining the statistical techniques underlying Nate Silver’s remarkably accurate predictions of the US presidential election. Bayes’ Theorem and hierarchical modelling both get a name check, but there are no equations. The article also includes a selection of #natesilverfacts.
Xavier Fernández i Marín, who maintains the jags package on Gentoo Linux, writes to tell me he is developing the R package ggmcmc. This package is for visualizing Markov Chain Monte Carlo output using ggplot2 graphics and should complement the existing plots for base and lattice graphics provided by coda. A comparison of all three graphical styles is given below. Continue reading
Bill Northcott’s binary distribution of JAGS 3.3.0 for Mac OS X is now available. This distribution supports 10.8 (Mountain Lion) and 10.7 (Lion). As explained by Bill in the installation manual, changes in Apple’s developer tools make it difficult to support earlier versions.
In response to a comment by Emmanuel Charpentier, I should write a few words about what has changed in JAGS 3.3.0.
The source tar ball and Windows installer for JAGS 3.3.0 are now available from Sourceforge. Binary packages for other platforms should be available shortly: see the JAGS homepage for details of how to get hold of a binary version for your platform.
In May we published an article on the burden of cancer attributable to infection in The Lancet Oncology. On the left is Figure 2 from the article, which shows that the majority of the burden is attributable to just four infectious agents. Continue reading
Back in December I wrote about the online machine learning course from Stanford, and how I was looking forward to the course on probabilistic graphical models (PGMs). Unfortunately the second course did not work out so well for me, despite my obvious interest in the topic, and I never completed it. The workload was simply too intense and the weekly deadlines were incompatible with my busy travel schedule during the springtime.
The Stanford courses are now part of an umbrella organization called Coursera, which is aggregating online courses from Universities all over the world. This 20-minute TED talk by Daphne Koller, co-founder of Coursera and lecturer on the PGM course, explains Coursera’s social mission. I now realise I am not really part of the target audience. In fact Coursera has its eye on the global marketplace for education. By removing financial and logistic barriers to entry they aim to make higher education accessible to people who would never otherwise have a chance to follow such courses.
An interesting point made by Koller is that online courses generate large amounts of data, which can be analyzed to improve the course the next time it is repeated. The same idea is reiterated by Peter Norvig in a 6-minute TED talk. Norvig’s talk also explains why the weekly deadlines – which I complained about above – are necessary to make these courses work.
Not discouraged by my failure on the PGM course, I have signed up for two autumn courses: Heterogeneous Parallel Programming and Functional Programming Principles in Scala. Both are relatively short (6 and 7 weeks respectively) so should be more manageable although I am sure I will have to give up one of them.