There has been a lot of attention paid to the role of US guns exacerbating the violence in Mexico. The assault-weapon ban expired on September 14, 2004, but with the recent spiraling of violence in Mexico the ban has attracted renewed attention. Just r...
Hello dear followers of R-bloggers.com Today (and probably in the next few days), R-bloggers will be down part of the time due to maintenance work. (Technical stuff: I am moving the site from shared hosting to VPS, and there seem to be a few bumps in the road) Sorry for the inconvenience, I will...
When I did a brief post three days ago I had no plans on writing two more posts on correlated random number generation. But I’ve gotten a couple of emails, a few comments, and some Twitter feedback. In response to my first post, Gappy, calls me out and says, “the way mensches do multivariate...
This is very short notice, but for those in the vicinity and not at the RSS conference, there is a highly interesting workshop taking place in Bristol in ten days (I would certainly have gone, had I not been at the same time in Banff!): We would like to invite you to contribute to...
Over the past 10 years, I have been torn between building a new stat. computing environment or trying to overhaul R. There are many issues on both sides. But the key thing is to enable doing new and better things in stat. computing rather than just making the existing things easier and more user-friendly....
A few weeks ago, I posted the Rffi package on the Omegahat repository. It is an interface to libffi which is a portable mechanism for invoking native routines without having to write and compile any wrapper routines in the native language. In other words, we can use this in R to call C routines...
We've covered how to generate random numbers in R before, but what if you want to go beyond generating one random number at a time? What if you want to generate two, or three or more random numbers, and what's more, you want them to be correlated? JD Long lays out the way in...
A new Metropolis-Hastings algorithm that I would call “universal” was posted by Somak Dutta yesterday on arXiv. Multiplicative random walk Metropolis-Hastings on the real line contains a different Metropolis-Hastings algorithm called the random dive. The proposed new value x’ given the current value x is defined by when is a random variable on ....
So, there’s probably an easier way to do this (please let me know if you know it)… Suppose you’re working with a system which creates (binary) files and posts them for download on a website. You know the names of the files that will be created. However, they may not have been made yet...
If I come across this kind of code when I'm checking (QCing) code it makes me want to punch the programmer's face. I find that it's impossible to step through and check each dataset with the previous incarnation. Which is how I check what h...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
