How to specify a data frame column using command line arg?
Hi Doug,
I think this will work for you:
adl1<-read.csv("test.csv")
adl1[,"a"]
[1] 1 4 7
so, adl1[,args[1]] should get you the column that you pass as the
first argument.
Jim
On Mon, Jun 6, 2016 at 5:45 AM, Douglas Johnson <todojo at gmail.com> wrote:
I'm guessing this is trivial but I've spent two hours searching and reading FAQ, tutorial, introductory and 'idiom' documents and haven't found a solution. All I want to do is select a data frame column at run time using a command line arg. For example, the "test.csv" file contains: a,b,c 1,2,3 4,5,6 7,8,9 If I run "test.r a", I get [1,4,7]. If I run "test.r b", I get [2,5,8]. Here's sample code -- how I map args[1] to column/vector 'a' or 'b' or 'c'? args <- commandArgs(trailingOnly=T) adl1<-read.csv(file="test.csv",head=T,sep=",") adl1$SOME-MAGIC-FUNCTION-OR-SYMBOL(args[1]) All I'm really trying to do is generate a bunch of scatter plots of column 'x' vs. 'y' without writing a separate program for each pair. Thanks, Doug -- http://www.dojopico.org <http://dojopico.org> [[alternative HTML version deleted]]
______________________________________________ R-help at 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.