HI, May be this helps.
set.seed(1) dat1<-data.frame(col1=rep(5,10),col2=rnorm(10,15),col3=rep(25,10),col4=rnorm(10,25)) dat1[sapply(dat1,function(x) sd(x)!=0)] # col2 col4 #1 14.37355 26.51178 #2 15.18364 25.38984 #3 14.16437 24.37876 #4 16.59528 22.78530 #5 15.32951 26.12493 #6 14.17953 24.95507 #7 15.48743 24.98381 #8 15.73832 25.94384 #9 15.57578 25.82122 #10 14.69461 25.59390 A.K. ----- Original Message ----- From: siddu479 <onlyfordigitalst...@gmail.com> To: r-help@r-project.org Cc: Sent: Tuesday, October 16, 2012 4:08 AM Subject: [R] Excluding all teh columns from a data frame if the standard deviation of that column is zero(0). Hi All, I have a data frame where nearly 10K columns of data, where most of them have standard deviation( of all rows) as zero. I want to exclude all the columns from the data frame and proceed to further processing. I tried like blow. *data <- read.csv("data.CSV", header=T) for(i in 2:ncol(data)) if(sd(data[,i])==0){ df[,i] <-NULL } * where I have the data columns from 2:ncol, but getting the error "Error in df[, i] <- NULL : object of type 'closure' is not subsettable" Can any one suggest the right method to accomplish this. ----- Sidda Business Analyst Lead Applied Materials Inc. -- View this message in context: http://r.789695.n4.nabble.com/Excluding-all-teh-columns-from-a-data-frame-if-the-standard-deviation-of-that-column-is-zero-0-tp4646310.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.