Hi, May be this helps: wells<-read.table("wells.txt",header=FALSE,stringsAsFactors=F)
wells2<-wells[-grep(".*\\_.*\\_",wells[,1]),] head(wells2) # V1 V2 #1 w7_1 0 #2 w11_1 0 #3 w12_1 0 #4 w13_1 0 #5 w14_1 0 #6 w15_1 0 wellsNew<-wells[grep(".*\\_.*\\_",wells[,1]),] head(wellsNew) # V1 V2 #851 99_10_4395 0 #852 99_10_4396 0 #853 99_10_4400 0 #854 99_10_4403 0 #855 99_10_4404 0 #856 99_10_4606 0 nrow(wells) #[1] 46366 nrow(wells2) #[1] 38080 nrow(wellsNew) #[1] 8286 38080+8286 #[1] 46366 A.K. ----- Original Message ----- From: emorway <emor...@usgs.gov> To: r-help@r-project.org Cc: Sent: Saturday, January 26, 2013 1:43 PM Subject: [R] a function more appropriate than 'sapply'? I'm wondering if I need to use a function other than sapply as the following line of code runs indefinitely (or > 30 min so far) and uses up all 16Gb of memory on my machine for what seems like a very small dataset (data attached in a txt file wells.txt <http://r.789695.n4.nabble.com/file/n4656723/wells.txt> ). The R code is: wells<-read.table("c:/temp/wells.txt",col.names=c("name","plc_hldr")) wells2<-wells[sapply(wells[,1],function(x)length(strsplit(as.character(x), "_")[[1]])==2),] The 2nd line of R code above gets bogged down and takes all my RAM with it: <http://r.789695.n4.nabble.com/file/n4656723/memory_loss.png> I'm simply trying to extract all of the lines of data that have a single "_" in the first column and place them into a dataset called "wells2". If that were to work, I then want to extract the lines of data that have two "_" and put them into a separate dataset, say "wells3". Is there a better way to do this than the one-liner above? -Eric -- View this message in context: http://r.789695.n4.nabble.com/a-function-more-appropriate-than-sapply-tp4656723.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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. ______________________________________________ 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.