The most visited post ever on the ‘Og was In{s}a(ne), my report on Radford Neal’s experiments with speeding up R by using different brackets (the second most populat was Ross Ihaka’s comments, “simply start over and build something better”). I just spotted two new entries by Radford on his blog that are bound to rekindle the debate about the speed of R. The latest one shows that matrix multiplication can be made close to ten time faster by changing the way testing for the presence of NaN’s in a matrix is operated. This gain is not as shocking as producing a 25% improvement when replacing x=1/(1+x) with x=1/{1+x}, but a factor 10 is such a major gain…