[gbrown]

R does actually ship with the ability to byte-compile functions these days, and as that functionality matures it may become the default behavior. It's still better to actually learn the language; it's far easier to optimize something like:

    apply(X, 1, function(x){
        # do stuff to the row of X
    })

than:

    for (i in 1:nrow(X)){
        # do stuff to X[i,], and store it somewhere
    }

[klmr]

As far as I know byte-compiling won’t actually alleviate the repeated name lookup (or does it?). Unless the R byte compiler is fiendishly clever, every single name lookup in the loop body will still incur what essentially amounts to a `get(name, environment(), inherits = TRUE)` call.

[gbrown]

Probably not, but I'll admit to not having dug into it too deeply. In my initial experiments, I found only modest speed gains when byte compiling. Then again, I'm already using C functions wherever possible.