People often ask for base functions to be made generic. There is a measurable cost:
> system.time(for(i in 1:1e6)seq(length=5)) [1] 18.603 0.016 18.621 0.000 0.000 > system.time(for(i in 1:1e6) seq.default(length=5)) [1] 12.515 0.012 12.533 0.000 0.000 > system.time(for(i in 1:1e6) NULL) [1] 0.234 0.017 0.251 0.000 0.000 > system.time(for(i in 1:1e6) rep(1, 5)) [1] 26.380 0.020 26.405 0.000 0.000 > system.time(for(i in 1:1e6) rep.default(1, 5)) [1] 17.504 0.017 17.525 0.000 0.000 > system.time(for(i in 1:1e6) rep.int(1, 5)) [1] 3.400 0.006 3.407 0.000 0.000 on one system (64-bit) and > system.time(for(i in 1:1e6) seq(length=5)) [1] 23.00 0.00 23.25 NA NA > system.time(for(i in 1:1e6) seq.default(length=5)) [1] 11.20 0.02 11.44 NA NA > system.time(for(i in 1:1e6) NULL) [1] 0.28 0.00 0.28 NA NA > system.time(for(i in 1:1e6) rep(1, 5)) [1] 30.21 0.02 30.70 NA NA > system.time(for(i in 1:1e6) rep.default(1, 5)) [1] 19.46 0.00 19.67 NA NA > system.time(for(i in 1:1e6) rep.int(1, 5)) [1] 1.97 0.00 1.97 NA NA on another (32-bit Windows). This may help explain why we have .int functions (e.g. rep.int and from 2.4.0, sort.int). -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
