Iris versicolor (Source: Wikipedia)R is a language, as Luis Apiolaza pointed out in his recent post. This is absolutely true, and learning a programming language is not much different from learning a foreign language. It takes time and a lot of pr... […]
Le Monde puzzle of last weekend was about sudoku-like matrices. Consider an (n,n) matrix containing the integers from 1 to n². The matrix is “friendly” if the set of the sums of the rows is equal to the set of the sum of the columns. Find examples for n=4,5,6. Why is there no friendly matrix […]
While preparing for the new semester I have started reimplementing standard NetLogo examples in R. The first is Fire model.The simulation in R is presented here:# Forest matrix trees encoding:# 3 – green, 2 – burning, 1 – burnt, 0 – no treesimu... […]
For fear of being left way behind as Martin Hawksey starts to get to grips with R, (see for example how he’s using R to automate the annotation of Google Spreadsheets with calculations that don’t come readily or efficiently to hand in Google Spreadsheets itself), I thought I better try to get to grips with […]
Another new local R user group has just started up, this time in Cleveland, OH. The Cleveland R User Group is the brainchild of R user Nicholas Hermez, and their first meeting on February 22 is a get-together to plan future topics, presenters and venues. If you're in the Cleveland area why not drop by and contribute your ideas? By the way, don't fo […]
Modifying R code to run in parallel can lead to huge performance gains. Although a significant amount of code can easily be run in parallel, there are some learning techniques, such as the Support Vector Machine, that cannot be easily parallelized. H... […]
I have for a while now wanted to learn how to do text mining in R. I have played a bit around with the tm package before, but nothing really serious. Being a Danish expat that might soon move back to Denmark with a Swiss girlfriend and child, the Dani... […]
Last week markbulling over at Drunks & Lampposts posted a method of using sapply to filter a list by a predicate. Today the @RLangTip tip of the day was to use sapply similarly. This made makes me wonder if R‘s … Continue reading → […]
I grabbed independent samples of 1500 recent users of the #newsnight and #bbcqt hashtags within a minute or two of each other about half an hour ago. Here’s who’s followed by 25 or more of the recent hashtaggers in each case. Can you distinguish the programmes each audience interest projection map relates to? Here’s the […]
I believe my survey experiment Survey Time illustrated later in this post and in Google’s Visualization of Survey Responses mainly pointed out how ignorant I am about the very complicated science of surveying from building the survey to the visualiza... […]