Here and there, I mentioned two codes to generated quasiPoisson random variables. And in both of them, the negative binomial approximation seems to be wrong. Recall that the negative binomial distribution is where and in R, a negative binomial di...

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I’ve had a few emails lately about forecast evaluation and estimation criteria. Here is one I received today, along with some comments. I have a rather simple question regarding the use of MSE as opposed to MAD and MAPE. If the parameters of a time series model are estimated by minimizing MSE, why do we

Following the posting on arXiv of the Statistical Science paper of Carvalho et al., and the publication by the same authors in Bayesian Analysis of Particle Learning for general mixtures I noticed on Hedibert Lopes’ website his rejoinder to the discussion of his Valencia 9 paper has been posted. Since the discussion involved several points

regor Gorjanc published an interesting article “Using Sweave with LyX” in R News in 2008, which (I believe) makes it much easier to use Sweave. I use command-line tools a lot every day, but I am still “GUI-addicted”. (I don’t want to comment more about Microsoft Word here.) LyX is a somewhat WYSIWYG tool based

Given the growing interest in parallel processing through GPUs or multiple processors, there is a clear need for a proper use of (uniform) random number generators in this environment. We were discussing the issue yesterday with Jean-Michel Marin and briefly looked at a few solutions: given p parallel streams/threads/processors, starting each generator with a random

I gave an informal talk on my Mac based “workflow” at Stanford on Friday. I talked a lot about Aquamacs as a tool for editing LaTeX (I use MacTeX) and for working with R (thanks auctex and ess, respectively). Skim also got a mention; I emphasized TeX-PDF synchronization. Some of the students were asking for

Two things that are crucial for a wider use of R among applied researchers. The first one is data manipulation/reshaping tool. I think the package "reshape" and "reshape2" have done good job and have largely removed the barrier. The second one is ...