When grading homeworks for my Monte Carlo graduate class, I found that my students had pointed out two typos in the exercises of Chapter 2 of “Introducing Monte Carlo Methods with R”.
– In Exercise 2.17, question d. should be “d. Show that the maximum of is attained at .“
– In Exercise 2.21, in item 
Life should be fun. I saw a post in R-help list saying Merry Christmas to other useRs, and I followed up by some R code which can produce a naive animation like this: Here is the code to generate the above Flash animation with shining Christmas: library(animation) saveSWF({ n = length(speed <- runif(angle <- runif(x
I love using TeXShop for GUI editing of LaTeX and particularly Sweave documents, but it is a pain not being able to get it to automatically generate the pdf output. Luckily I found this post which explains how to add a Sweave engine.Basically, make a f...
I love using TeXShop for GUI editing of LaTeX and particularly Sweave documents, but it is a pain not being able to get it to automatically generate the pdf output. Luckily I found this post which explains how to add a Sweave engine.Basically, make a f...
In 2006 UserR conference Jim Porzak gave a presentation on data profiling with R. He showed how to draw summary panels of the data using a combination of grid and base graphics. Unfortunately the code has not (yet) been released as a package, so when I recently needed to quickly review several datasets at the 
After recently having to think critically about the value of various R packages for social science research, I realized that others might find value in a post on “must-have” R packages for social scientists. After the immensely popular post on this topic for Python packages a follow-up seemed appropraite. If you conduct social
At long last pgfSweave has finally made its way to CRAN. http://cran.r-project.org/web/packages/pgfSweave/index.html The pgfSweave R package is about speed and style of graphics. For speed, the package provides capabilities for “caching” graphics generated with Sweave on top of the caching funcitonality of cacheSweave. For style the pgfSweave package facilitates the integration of R graphics with
LaTeX is a typesetting language that is known for its beautiful mathematical formulas. It is similar to HTML in that you write your document in plain text and process (or compile) it to create a postscript or PDF file. You will need to download a LaTeX processor for your platform. On Windows, TeXnicCenter (http://www.texniccenter.org/) is
I finally pushed highlight to CRAN, which should be available in a few days. The package uses the information gathered by the parser package to perform syntax highlighting of R code The main function of the package is highlight, which takes a numb...
Estimating a proportion at first looks elementary. Hail to aymptotics, right? Well, initially it might seem efficient to iuse the fact that . In other words the classical confidence interval relies on the inversion of Wald’s test.
A function to ease the computation is the following (not really needed!).
waldci<- function(x,n,level){
phat<-sum(x)/n
results<-phat + c(-1,1)*qnorm(1-level/2)*sqrt(phat*(1-phat)/n)
print(results)
}
An exact confidence interval is 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
