Speeding up parentheses (and lots more) in R

As I noted here, enclosing sub-expressions in parentheses is slower in R than enclosing them in curly brackets. I now know why, and I’ve modified R to reduce (but not eliminate) the slowness of parentheses. The modification speeds up many other operations in R as well, for an average speedup of something like 5% for programs that aren’t dominated by large built-in operations like matrix multiplies.

Two Surpising Things about R

I see that it’s been over a year since my last post!  I have a backlog of blog post ideas, but something else always seems to have higher priority.   Today, though, I have some interesting (and useful) things to say about R, which I discovered in the last few days, and which shouldn’t take long to blog about.  Of course, some other people may already be quite familiar with these things.  Or maybe not…

First up, a useful feature of R that I hadn’t realized existed, which comes with a surprising gain in efficiency.  Second, something surprisingly slow about R’s implementation of a very common operation.