Have you used colClasses to define what each of the columns contain? Can you use 'scan'? I haven't tried anything with 500,000 columns, but if they are numeric, this should not take too long. So I create a 20 line file with 500,000 columns and here is what it took reading it both as numeric and character:
> system.time(x <- scan('/tempyy.txt', what=0)) Read 10000000 items [1] 17.57 0.12 18.89 NA NA > str(x) num [1:10000000] 12345 12345 12345 12345 12345 ... > system.time(x <- scan('/tempyy.txt', what='')) Read 10000000 items [1] 9.03 0.10 11.21 NA NA > str(x) chr [1:10000000] "12345" "12345" "12345" "12345" "12345" "12345" "12345" "12345" ... > On 2/27/07, andy1983 <[EMAIL PROTECTED]> wrote: > > > I have been using the read.csv function for a while now without any > problems. > My files are usually 20-50 MBs and they take up to a minute to import. > They > have all been under 50,000 rows and under 100 columns. > > Recently, I tried importing a file of a similar size (which means about > the > same amount of data), but with ~500,000 columns and ~20 rows. The process > is > taking forever (~1 hour so far). In Task Manager, I see the CPU is at max, > but memory slows down to a halt at around 50 MBs (far below memory limit). > > Is this normal? Is there a way to optimize this operation or at least > check > the progress? Will this take 2 hours or 200 hours? > > All I was trying to do is transpose my extra-wide table with a process > that > I assumed would take 5 minutes. Maybe R is not the solution I am looking > for? > > Thanks. > > -- > View this message in context: > http://www.nabble.com/read.csv-size-limits-tf3302366.html#a9186136 > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? [[alternative HTML version deleted]] ______________________________________________ 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.