Hello, Try this: idx<-sapply(file,function(x) all(unique(x)==1)) file[!idx] # V2 V3 V4 V6 V7 V8 V9 #1 0 2 2 1 5 1 1 #2 0 2 2 1 5 1 1 #3 0 2 2 2 5 2 2 #4 0 2 2 1 5 1 1 #5 0 2 2 0 5 0 2 #6 0 2 2 1 5 1 0 A.K.
----- Original Message ----- From: Kate Dresh <dreshk...@gmail.com> To: r-help@r-project.org Cc: Sent: Friday, August 24, 2012 8:11 PM Subject: [R] remove column *Hi all,* I'm trying to filter a file through the columns. This file below is a example of my data frame. My true data frame has seven hundred thousand columns and 500 hundred lines. I need to identify and to remove all columns that all elements equal a number 1. In this my case, columns were deleted are number 1,5 and 10. file <-read.table(text=" 1 0 2 2 1 1 5 1 1 1 1 0 2 2 1 1 5 1 1 1 1 0 2 2 1 2 5 2 2 1 1 0 2 2 1 1 5 1 1 1 1 0 2 2 1 0 5 0 2 1 1 0 2 2 1 1 5 1 0 1 ",sep="",header=FALSE) the result after the filter will be 0 2 2 1 5 1 1 0 2 2 1 5 1 1 0 2 2 2 5 2 2 0 2 2 1 5 1 1 0 2 2 0 5 0 2 0 2 2 1 5 1 0 I used this commands idlength<-sapply(file,function(x) length(unique(x)) ), but came an error message: caught segfault *** address 0x4, cause 'memory not mapped' *My question: is it possible to remove the all columns from above file to *achieve* the desired result?* * * * **Thank you for help* Kate Dresh [[alternative HTML version deleted]] ______________________________________________ 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.
