R Programming By Example

Profiling fundamentals with Rprof()

Even experienced programmers have a hard time identifying bottlenecks in their code. Unless you have quite a bit of experience and a good sense of what parts of your code are slowing down its execution, you're probably better-off profiling your code before you start optimizing it. Only once you've identified the most important bottlenecks can you attempt to eliminate them. It's difficult to provide general advice on improving performance since every implementation is quite different.

The Rprof() function is a built-in tool for profiling the execution of R functions. At regular intervals, the profiler stops the interpreter, records the current function call stack, and saves the information to a file. We ...