Sometimes a minor change to your R code can make a big difference in processing time. Here is an example showing that if you’re don’t care about the names attribute when unlist():ing a list, specifying argument use.names = FALSE can speed up the processing lots!
> x <- split(sample(1000, size = 1e6, rep = TRUE), rep(1:1e5, times = 10)) > t1 <- system.time(y1 <- unlist(x)) > t2 <- system.time(y2 <- unlist(x, use.
The below code shows how to configure the help.ports option in R such that the built-in R help server always uses the same URL port. Just add it to the .Rprofile file in your home directory (iff missing, create it). For more details, see help("Startup").
# Force the URL of the help to http://127.0.0.1:21510 options(help.ports = 21510) A slighter fancier version is to use a environment variable to set the port(s):
The below code shows how to configure the repos option in R such that install.packages() etc. will locate the packages without having to explicitly specify the repository. Just add it to the .Rprofile file in your home directory (iff missing, create it). For more details, see help("Startup").
local({ repos <- getOption("repos") # http://cran.r-project.org/ # For a list of CRAN mirrors, see getCRANmirrors(). repos["CRAN"] <- "http://cran.stat.ucla.edu" # http://www.stats.ox.ac.uk/pub/RWin/ReadMe if (.Platform$OS.type == "windows") { repos["CRANextra"] <- "http://www.
