This is an overview of tools for speeding up your R code that I wrote for the Davis R Users’ Group.
It’s customary to quote Donald Knuth at this point, but instead I’ll quote my twitter buddy Ted Hart to illustrate a point:
I’m just going to say it.I like for loops in #Rstats,...
by Joseph Rickert Baseball fans have been serious about statistics since Carl Pearson was a young man (although I doubt that Carl followed the game). It is not clear, though, exactly when baseball statisticians moved from doing descriptive stats into predictive analytics. In his book Super Crunchers, Ian Ayers credits Bill James of Baseball Abstract fame for getting this...
Several R packages provide an interface to query map services (Google Maps, Stamen Maps or OpenStreetMap) to obtain raster images …
Concerto is a open source R Content Management System for developing online applications. The primary purpose of Concerto is for the designing of online tests. However, the hard working programmers at the University of Cambridge Psychometrics Centre have created a program that is flexible enough to address a wide range of applications such as the development of statistical learning...
I’m a big fan of open-source software for research. For example, R-statistics, Qgis, and Grass GIS are awesome programs. R can do any statistical tests and numerical modeling you can imagine; if there’s not a built-in function you can write … Continue reading →
For some cryptic reason I needed a function that calculates function values on sliding windows of a vector. Googling around soon brought me to ‘rollapply’, which when I tested it seems to be a very versatile function. However, I wanted to code my own version just for vector purposes in the hope that it may 
Thanks to a helpful SO-Answer I was able to download all CLC vector data (43 zip-files) programmatically:
require(XML)
path_to_files dir.create(path_to_files)
setwd(path_to_files)
doc urls
# function to get zip file names
get_zip_name
# function to plug into sapply
dl_urls
# download all zip-files
sapply(urls, dl_urls)
# function for unzipping
try_unzip
# unzip all files in dir and delete them afterwards
sapply(list.files(pattern = "*.zip"),...
Last year I sat on a couple of panels organised by I’m a Scientist’s Shane McCracken at various science communication conferences. A couple of days ago, I noticed Shane had popped up a post asking Who are you Twitter?, a quick review of a social media mapping exercise carried out on the followers of the 
Identifying project stakeholders and their requirements is a very important factor in the success of any project. Existing techniques tend to be very ad-hoc. In her PhD thesis Soo Ling Lim came up with a very interesting solution using social network analysis and what is more made her raw data available for download I have
(This article was first published on G-Forge » R, and kindly contributed to R-bloggers) Sitting with a data set with too many variables? The SVD can be a valuable tool when you’re trying to sift through a large group of continuos variables. The image is CC by Jonas in China. It can feel like a daunting task when you...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
