On 10/11/2011 10:28 AM, R. Michael Weylandt wrote:
Yes, there will be some reduction in speed:E.g., > system.time(replicate(1e5, (function() sum(1:10))())) user system elapsed 0.696 0.022 0.729 > system.time(replicate(1e5, sum(1:10))) user system elapsed 0.292 0.006 0.306 But it's not much: 3 tenths of a second for 10,000 calls. It's certainly worth it for ease of readibility and debugging.
I don't think your test is valid: you're not just calling the function in the upper loop, you're creating it too. Here's what I see:
First, the version I complained about: > system.time(replicate(1e5, (function() sum(1:10))())) user system elapsed 0.35 0.00 0.35 Now a more realistic one: > f <- function() sum(1:10) > system.time(replicate(1e5, f())) user system elapsed 0.25 0.00 0.25 Now the version with no function call: > system.time(replicate(1e5, sum(1:10))) user system elapsed 0.23 0.00 0.24 So creating a function is expensive, but calling one isn't so bad. Duncan Murdoch ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
