> dt1[ vapply(dt1, FUN=is.numeric, FUN.VALUE=NA) ] a c 1 1 1.1 2 2 1.0 ... 10 10 0.2
Bill Dunlap TIBCO Software wdunlap tibco.com On Fri, Apr 29, 2016 at 9:19 AM, Carl Sutton via R-help < r-help@r-project.org> wrote: > Good morning RGuru's > I have a data frame of 575 columns. I want to extract only those columns > that are numeric(double) or integer to do some machine learning with. I > have searched the web for a couple of days (off and on) and have not found > anything that shows how to do this. Lots of ways to extract rows, but not > columns. I have attempted to use "(x == y)" indices extraction method but > that threw error that == was for atomic vectors and lists, and I was doing > this on a data frame. > > My test code is below > > # a technique to get column classes > library(data.table) > a <- 1:10 > b <- c("a","b","c","d","e","f","g","h","i","j") > c <- seq(1.1, .2, length = 10) > dt1 <- data.table(a,b,c) > str(dt1) > col.classes <- sapply(dt1, class) > head(col.classes) > dt2 <- subset(dt1, typeof = "double" | "numeric") > str(dt2) > dt2 # not subset > dt2 <- dt1[, list(typeof = "double")] > str(dt2) > class_data <- dt1[,sapply(dt1,is.integer) | sapply(dt1, is.numeric)] > class_data > sum(class_data) > typeof(class_data) > names(class_data) > str(class_data) > Any help is appreciated > Carl Sutton CPA > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.