Gabor Grothendieck wrote: > > What OS was that on? > I suppose you are asking me :-) >> BTW, I found that using things directly in R is _much_ >> slower than creating a batch file and then running it. >> >> For example, I had a directory with misnamed mp3 files, >> and I wanted to use R to rename and copy them >> to another directory. I tried to use file.copy, but it >> took too much time. Writing a batch file and then running >> it was much faster.
I was Windows, of course. In Linux, I would use a one-line script with find, mv, sed, etc. If you want to test, do this: # create subdiretory source_dir with 800 files # (for simplicity's sake, all files with decent names: no # spaces, no non-ascii characters, etc) # create empty subdiretory dest1_dir # create empty subdiretory dest2_dir # arr <- list.files("source_dir") t0 <- Sys.time() # 1st test: slow for (x in arr) file.copy(paste("source_dir/", x, sep=""), "dest1_dir") t1 <- Sys.time() t1 - t0 # 2nd test: fast sink("batch_file.bat") for (x in arr) cat("copy source_dir\\", x, " dest2_dir\\\n", sep="") sink() system("batch_file.bat") t2 <- Sys.time() t2 - t1 Hmmm.... Interesting... I did this test with 47 files, and I got: t1 - t0 Time difference of 11.439 secs t2 - t1 Time difference of 11.969 secs Oops... Alberto Monteiro ______________________________________________ R-help@stat.math.ethz.ch 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.