Hi,
On Jul 9, 2009, at 11:40 AM, Juliet Hannah wrote:
> Hi,
>
> #make example data
> dat <- data.frame(matrix(rnorm(15),ncol=5))
> colnames(dat) <- c("ab","cd","ef","gh","ij")
>
> If I want to get a subset of the data for the middle 3 columns, and I
> know the names of the start column and the end column, I can do this:
>
> mysub <- subset(dat,select=c(cd:gh))
>
> If I wanted to do this just on the column names, without subsetting
> the data, how could I do this?
>
> mynames <- colnames(dat);
>
> #mynames
> #[1] "ab" "cd" "ef" "gh" "ij"
>
> Is there an easy way to create the vector c("cd","ef","gh") as I did
> above using something similar to cd:gh?
How about just taking your mynames vector? eg:
R> mynames[2:4]
[1] "cd" "ef" "gh"
R> dat[, mynames[2:4]]
cd ef gh
1 1.7745386 1.0958930 -0.07213304
2 0.7480372 -0.1364458 -0.62848211
3 -0.5477843 1.5811382 -0.74404103
-steve
--
Steve Lianoglou
Graduate Student: Physiology, Biophysics and Systems Biology
Weill Medical College of Cornell University
Contact Info:
http://cbio.mskcc.org/~lianos______________________________________________
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