I’m writing this post for two reasons: i) someone searched on Google for the term “what is ordisurf doing” and ended up on my blog, and ii) because I have been on the receiving end of reviewers comments on a … Continue reading →

My neighbour is an half-retired entrepreneur who still runs his electric engine company. A few weekends ago, he came to me with the following physics question related with one of those engines: given a primary disk rotating at the angular speed of ω0 and a secondary disk located on the first one with a centre

Thanks to this great post http://www.imachordata.com/?p=730 we can now put multiple plots on a display with ggplot2. This provides somewhat similar functionality to ‘par(mfrow=c(x,y))’ which would allow multiple plots with the base plot function. gridExtra doesn’t have quite the same level of options as ‘par’, but the syntax is simple. grid.arrange( graph1, graph2, ncol=2 Simple. ‘grid.table’

In case you missed them, here are some articles from May of particular interest to R users. A review of "R Cookbook", a new how-to book for R programmers. A detailed example of using the RevoScaleR package to analyze a large airline data set. A new guide for R beginners, "How to Learn R", provides links to R resources,...

Following the trend of one liners for various languages (Haskell, Scala, Python), here's some examples in RMultiply Each Item in a List by 2#listslapply(list(1:4),function(n){n*2})# otherwise(1:4)*2 Sum a List of Numbers#listslapply(list(1:4),sum)# oth...

I have been using R for about two years, with no previous coding background. So, I feel like the title says, “always learn and never know”. This time, I decided to use R to study a simple, non-statistical problem that came up some time ago. Suppose the exponential function 2^x and the parabola x^2. One