Using builtin data frame anscombe try this. First we set up a data frame anscombe.seq which has one row containing 1, 2, 3, ... . Then select out from that data frame and unlist it to get the desired index vector.
> anscombe.seq <- replace(anscombe[1,], TRUE, seq_along(anscombe)) > idx <- unlist(subset(anscombe.seq, select = c(x1, x3:x4, y2))) > anscombe[idx] x1 x3 x4 y2 1 10 10 8 9.14 2 8 8 8 8.14 3 13 13 8 8.74 4 9 9 8 8.77 5 11 11 8 9.26 6 14 14 8 8.10 7 6 6 8 6.13 8 4 4 19 3.10 9 12 12 8 9.13 10 7 7 8 7.26 11 5 5 8 4.74 On 8/26/07, Muenchen, Robert A (Bob) <[EMAIL PROTECTED]> wrote: > Hi All, > > I'm using the subset function to select a list of variables, some of > which are contiguous in the data frame, and others of which are not. It > works fine when I use the form: > > subset(mydata,select=c(x1,x3:x5,x7) ) > > In reality, my list is far more complex. So I would like to store it in > a variable to substitute in for c(x1,x3:x5,x7) but cannot get it to > work. That use of the c function seems to violate R rules, so I'm not > sure how it works at all. A small simulation of the problem is below. > > If the variable names & orders were really this simple, I could use > indices like > > summary( mydata[ ,c(1,3:5,7) ] ) > > but alas, they are not. > > How does the c function work this way in the first place, and how can I > make this substitution? > > Thanks, > Bob > > mydata <- data.frame( > x1=c(1,2,3,4,5), > x2=c(1,2,3,4,5), > x3=c(1,2,3,4,5), > x4=c(1,2,3,4,5), > x5=c(1,2,3,4,5), > x6=c(1,2,3,4,5), > x7=c(1,2,3,4,5) > ) > mydata > > # This does what I want. > summary( > subset(mydata,select=c(x1,x3:x5,x7) ) > ) > > # Can I substitute myVars? > attach(mydata) > myVars1 <- c(x1,x3:x5,x7) > > # Not looking good! > myVars1 > > # This doesn't do the right thing. > summary( > subset(mydata,select=myVars1 ) > ) > > # Total desperation on this attempt: > myVars2 <- "x1,x3:x5,x7" > myVars2 > > # This doesn't work either. > summary( > subset(mydata,select=myVars2 ) > ) > > > > ========================================================= > Bob Muenchen (pronounced Min'-chen), Manager > Statistical Consulting Center > U of TN Office of Information Technology > 200 Stokely Management Center, Knoxville, TN 37996-0520 > Voice: (865) 974-5230 > FAX: (865) 974-4810 > Email: [EMAIL PROTECTED] > Web: http://oit.utk.edu/scc, > News: http://listserv.utk.edu/archives/statnews.html > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.